


Teasing Is A Sport

by Underblogger



Category: Undertale (Video Game)
Genre: Dating, Drinking, Eventual Smut, F/F, F/M, Female Reader, Female!Reader - Freeform, Magic, Monsters, Party, Past Abuse, Reader Is Not Frisk, Smut, Teasing, Vaginal Fingering, relationship games, undertale - Freeform
Language: English
Status: Completed
Published: 2016-01-11
Updated: 2016-04-27
Packaged: 2018-05-13 06:03:59
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 22
Words: 43,447
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5697721
Author URL: https://archiveofourown.org/users/Underblogger/pseuds/Underblogger
Summary: <blockquote class="userstuff">
              <p>When you start playing a less-than-innocent game with Sans, your world changes. You're determined to put him in a frenzy of wanting, but he drives you crazy and you know you need him. How far can you both go with it until your feelings get in the way?<br/>Post-pacifist ending, monsters have been on the surface for 4 months and the reader is living with the skelebros.</p>
            </blockquote>





	1. A Rather Disappointing Meal And A Badly Made Plan

**Author's Note:**

> I also have a Tumblr - underblogger.tumblr.com ! Feel free to ask me any questions about my work there, or just talk to me about it!

"HUMAN! WOULD YOU LIKE SOME SPAGHETTI?"  
A strong beam of light and a loud, shrill voice woke you from your peaceful sleep, but you only rolled back over. Maybe if you pretended that you were still asleep he would go away and let you have just 5 more minutes.  
"HUMAN? I KNOW YOU ARE AWAKE!" The voice continued. You only groaned loudly in response.  
"Papyrus, it's 9AM, it's way too early for spaghetti." You grumbled.  
"BUT HUMAN, IT IS NEVER TOO EARLY FOR SPAGHETTI! I WILL MAKE YOU SOME, GET DRESSED!" You heard him say as he left the room. Another sleepy groan escaped your lips as you slowly sit up. It had been 4 months since the barrier had been lifted and monsters returned to normal society again. Since moving out of the underground, most monsters had piled into the closest city to Mt. Ebott, where places such as Alphys' lab, Grillby's had been rebuilt. You lived with Sans and Papyrus in a cosy house that was pretty close to your other friends.  
As you slowly shuffled over to the shower, you heard a small whoosh of flames being ignited below you. Clearly, Papyrus had his heart set on making you spaghetti on this early Saturday morning, and once he got something in his head it was hard to dissuade him from it.  
As the warm water ran over your skin, you contemplated the two skeleton brothers that you lived with. Papyrus was a sweetheart, and you both had soon realised that not only did you understand each other very well, but you were both good at listening to each other's problems. Your bond with Papyrus had been unexpected, but a very close one - you would probably count him as one of your best friends. On the other hand, Sans was a whole other matter. It had started as a great friendship, but lately you had noticed something... different in the way you felt about him. In the way he acted around you. It felt like you both felt something, but were too scared to admit it to the other, and often disguised it in shameless flirting and countless jokes. Just thinking about him made you blush and smile.  
"Shit." You exclaimed as you got out of the shower. Whilst you'd been so busy thinking, you'd forgotten to bring a towel with you into the bathroom, and now was soaking wet with no means of drying off.  
You peeked your head round the door. You could easily heard Papyrus downstairs, so he wasn't an issue, but you didn't know where Sans was. You hoped he was asleep. He was probably asleep.  
Daringly, you decided to quickly run naked back to your room to dry off.  
One last look out of the door.  
Slowly, you creaked the door open, still cautious.  
You stepped one slow foot out of the door. Still no one.  
You began to run, trying to make your footsteps as light as possible, but they were annoyingly loud and clunky. Your heart was beating unbelievably fast, it was like you could feel every pump inside your chest.  
Finally, you got to your room and slammed the door behind you, panting. You knew that you shared a wall with Sans' room and you probably just woke him, but it didn't matter as long as no one saw what you just did. You quickly got dressed, dried your hair, and applied make up. The sooner you could get downstairs and forget what just happened, the better. You got up and swung your door open, ready to go downstairs and eat a horrifically inappropriate spaghetti breakfast.  
"Forget your towel, kid?" A gruff voice chuckled. You froze. Sans was outside your door, grinning at you.  
"Um, I don't know what you're talking about." You stutter, feeling the blush spread to your cheeks.  
"Heheh, sure kiddo. Just next time you feel like running around the house naked, tell me first okay? I wanna actually see it." He laughs. You sigh in relief at his last words, having realised he hadn't seen you. You pushed questioning how he knew you'd done it if he hadn't seen it to the back of your mind as you tried to think of a witty retort.  
"Who says you'll _ever_ see it?" You managed to smirk as you descended the stairs. You heard him snort with laughter in response, before you entered the kitchen.  
"HUMAN!" Papyrus exclaimed as you walked in, "YOU ARE JUST IN TIME!"  
Eating spaghetti and meatballs for breakfast was always very weird, but you did it to please Papyrus. It was only every so often that he insisted on making it so early, but you knew it would break his heart if you refused it.  
"Hey Pap, mind using less sauce in the early morning?" You mumble after you finish. Papyrus grins at you.  
"ANYTHING TO MAKE IT BETTER!" He grins. "BY THE WAY HUMAN, WOULD YOU LIKE TO COME WITH ME AND SANS FOR DINNER AT GRILLBY'S TONIGHT?"  
"Yeah, sure!" You smiled.  
"WE WILL LEAVE THE HOUSE AT 6!" Papyrus said as he left the room. You heard him leave the house to go attend to his guard duties with Undyne, and after noting that it was 10AM, you knew Sans had probably left the house for one of his jobs by now as well.  
Most of your day off work was split between playing video games and watching countless anime that Alphys had recommended for you. Some of it was pretty good, but a lot of it was very hard to follow. Anime was something you would watch a lot, but the stuff Alphys watched was more hectic and confusing than anything you would normally watch. You felt a little guilty for wasting a sunny day, but at the same time you knew you'd be going out with your two skeleton pals later - so you were going to go outside at SOME point.  
Around 15 minutes before you were due to set off, the door loudly opened and shut below you.  
"Hello!" You called down the stairs, pausing Mew Mew Kissy Cutie 2.  
"HUMAN!" Papyrus called back. You nearly started to yell back to ask how he was, but realised it was probably better to just go talk to him.  
As you reached the front door, you realised Papyrus didn't look like he was going to stay in the house for very long. He had made no move to take his shoes off and was still stood right next to the door.  
"HUMAN, UNDYNE HAS CALLED ME AND NEEDS SOME HELP THIS EVENING. I'M SORRY, BUT YOU AND SANS WILL HAVE TO HAVE DINNER WITHOUT ME!" He explained energetically before turning to leave. Clearly, you and Sans would be having dinner alone tonight - an exciting but nerve-racking prospect.  
"Wait, Papyrus!" You said, and he turned back around slowly.  
"YES?" He asked.  
"Papyrus... I'm going to tell him tonight." You almost whispered. He already knew about your feelings towards Sans, as you talked to him about it quite often.  
"WHAT AN EXCELLENT IDEA! I THINK IT WILL GO WELL, HUMAN!" He grinned before walking out of the door.  
"What does THAT mean?" You desperately questioned, but he had already walked out of the door.  
"I think it will go well?" You repeated, trying to make sense of it.  
"What will go well?" A gruff voice asked. You jumped and turned around to see Sans standing there, blue coat on and ready to go.  
"What? Nothing. When did you get home?" The words tumbling out of your mouth were quick and panicked, worried that he had heard you tell your plan to Papyrus.  
"Not long ago. Wanna head out? My brother already called me and said he's busy." Sans drawled.  
"Uh, sure." You stuttered, still in shock.  
-  
Grillby's was as full as ever when you and Sans arrived. Taking a small booth to the side of the room, Sans ordered you both a burger and a whiskey for himself. Your conversation as you waited for your food was as normal as ever, talking about each other's days and making terrible jokes. When the food was brought over, you mustered all of your courage.  
"Look, Sans, there's something I need to tell you." You declared, proud of how confident it sounded.  
"Yeah, kiddo?" He replied, causally, unblinking. You took a deep breath.  
"Sans, I wanted to tell you that..." You trailed off, feeling your hands shake. _This is stupid_ , you told yourself. _I shouldn't be so nervous. Pull yourself together!_  
"Come on, spit it out!" he drawled, a little smile tugging at the corners of his skeletal mouth.  
"I like you." You blurted out. His face dropped. He remained silent. You started to panic.  
"I like, LIKE like you." You continued. "I like you in a way more than just friends." Sans never once broke eye contact with you, the point of light in his sockets following your every move. He softly spoke your name, but nothing more.  
"Uh... Sans?" You softly uttered, hardly daring to breathe. "I need you to reply..."  
Suddenly, the skeleton stood up, downed his whiskey, and grabbed his burger.  
"Sorry." He said, before looking away.  
"Sans?" You desperately said, feeling panic and shame bring tears to your eyes. The skeleton didn't look at you and started to walk away.  
"Wait!" You cried as you grabbed his arm, stopping him. "Wait, just forget I said that, can we go back to normal? We can pretend I didn't say it. We can pretend that didn't happen. Please!" You desperately rambled. He didn't turn back to look at you, simply tugged his arm away and abruptly left.  
Adrenaline rushing through your system, you ran out after him. You wanted to stop him, to try and get a real explanation, or for him to say anything else. Cold air hit you as you flung the door open and desperately searched the night for your room-mate. Despite the street being empty, Sans was gone.  
A desperate sob left your lips. You had ruined everything. Scary images of being kicked out of the house and losing your unique monster friends flashed before your eyes. What if they all thought I was an idiot now, a loser? You could only crumple up in a ball in fear, uncaring of how it looked to anyone who would walk past, trying to regain control of your rapid breathing. Eventually, you were able to calm down and started to see sense. If Sans didn't like you, then you would just have to see past it and try to be friends. Exhausted, you began the walk home.  
-  
As your thoughts were occupied you didn't notice the journey at all, and it felt like it had taken only 10 seconds. As you arrived home, you simply went up to your room, got into bed, and curled up in a ball. You lay there for what must have been hours, repeating that fatal conversation in your head over and over again. Ages later, the creaking of a door downstairs interrupted your thoughts.  
"I AM HOME!" A loud voice declared. A smile broke through your heartbroken expression at Papyrus' relentless cheerfulness.  
"...hello..." You croaked down to him, not expecting him to hear it. However, you heard the grunts of someone trying very hard to take shoes off as fast as possible, and then a shriek as that person fell over. Feet rushed up the stairs.  
"HUMAN!" Papyrus cried as he burst into your room. When he saw you, his expression fell and he rushed over. "Human? Why are you upset?"  
"I... I..." You hiccuped. Just thinking about it made you want to cry again. "I... told Sans how I felt. He rejected me. I think he... hates me..." Papyrus stroked your hair with a slender, skeletal hand. You slowly sat up, so that he could sit next to you on the bed. Neither of you spoke for a long time.  
"That's very odd." Papyrus finally said. Confusion filled you up.  
"What? What is?" You asked, incredulous.  
"My brother... He told me that he liked you, he said that he had feelings for you."  
"He said... He said that?"  
"I have spoken to him about it more than once."  
You could hardly believe the words you were hearing. Sans had looked you in the eye and made it clear he didn't reciprocate your feelings.  
"Papyrus..." You began. "Does Sans lie to people very often?" You slowly asked.  
"Sometimes." Papyrus cryptically replied. You both fell silent again, but your mind was whirring.  
He's playing hard to get, you thought. He's trying to appear unavailable. You slowly started to wonder what would happen if you were to push Sans. You knew even if he lied to you, he wouldn't lie to his brother. What Sans needed now was a little convincing - a little push in the right direction. Wiping your tears away, you quickly formed a plan.  
"Pap, can you do me a favour?" You asked. Next to you, your skeleton friend beamed.  
"Anything, if it will cheer you up!" He joyfully replied.  
"Call Mettaton, okay? Tell him I'm holding a party tomorrow night. He always knows who to invite." At these words, Papyrus lit up.  
"OH, I LOVE PARTIES!" He exclaimed, jumping to his feet. "I'LL TELL EVERYONE!"  
As Papyrus left, you began quickly sorting through your wardrobe. Thinking about what you would wear tomorrow, you quickly picked out some lacy black lingerie as well as a red dress that showed off your cleavage. You smiled to yourself as you got into bed. You would show Sans just what he was missing, You would convince Sans that he'd made the wrong decision. Teasing was what you needed to do, and teasing was your forte.


	2. Party Preparations and an Annoying Planner

**Summary for the Chapter:**

> Clearly, Mettaton heard about, and was very excited about, your party.

The next morning, you were roughly lifted straight out of bed by someone with very hard limbs. For a small second, you thought they might be bones and snapped your eyes open with joy. However, your happiness was subdued when you realised that they were the metal arms of a robot, instead.

"Hello, darling!" Mettaton beamed down at you. "Dear Papyrus told me about the party last night, and I knew I simply MUST come over to help you set it up!" You groaned, and shuffled slightly as he began to carry you out of your room.

"It's... what... Mettaton, what time is it?" You blundered, desperately trying to stay awake. Above you, you could only hear the whirs and clicks of the mechanics inside his chest panel, which you were cradled against. Suspicion grew inside the pit of your stomach. "Mettaton...? The time?" You slowly questioned.

"It's a little early, but we will need all the time we can get, I promise!" The robot beamed, avioding your question.

"It better be after 9AM." You warned.

There was a long pause.

"Don't check the clock then, darling." Mettaton smiled guiltily. _For God's sake,_ you thought. _One day_ _I'll dismantle this robot by hand._

After Mettaton had dumped you down in the bathroom and ordered you to shower, he'd decided to take you out shopping for party supplies. In the very first shop, he'd only stared at you disappointedly when you made a beeline for the alcohol section. After a long time deciding, you ended up buy 4 crates - a mix of beer and cider - as well as several spirits such as whisky and vodka to mix with the fizzy drinks you had insisted on getting. Clearly, 'mixers' was not slang that had reached the underground. Finally, Mettaton had insisted you buy some wine to go with this mix to add 'as much class as we can redeem'. After that, you had been thoroughly dragged round practically every decorating shop in the city. It took a particularly long time, because around every corner Mettaton seemed to bump into fans, monster or human, and was so grateful that he'd made it big up on the surface that he would spend really long amounts of time talking to them. By the time you'd gotten home, it was 5PM and getting dark. As he rushed you upstairs to get ready, you could hear him whizzing around downstairs, trying to put up the horrendous amount of decorations he'd bought.

You went slowly whilst getting ready. You knew that after what had happened last night, you needed to look as close to perfect as possible tonight. The best part was that you knew Sans would have to attend, seeing as it was his house as well as yours. Suddenly, doing your hair was interrupted as someone threw the door open and shouted your name loudly.

"Uh, what? Hello?" You stammered as you turned round. Undyne was stood in the doorway, grinning at you, and you felt extremely glad you had gotten dressed before anything else.

"Is that the dress you're wearing? It's perfect!" She beamed, immediately shutting the door behind her and rushing over to you.

"Thanks! Do you mind if I start doing my makeup whilst you're in here?"

"Not at all! I know you'll be wanting to look especially hot, eh?" She winked. A little shiver crept up your spine.

"What are you winking at?" You asked, _really_ hoping she didn't know about what had happened with Sans.

"Papyrus told me. About... you know who." She gloated.

"You _know_ about that?!" You exclaimed. This was a nightmare. The last thing you wanted was for everyone to know, because you didn't want word of your little plan getting out and possibly being told to Sans. Undyne giggled furiously, gleefully clapping her hands together and sitting heavily down onto your bed.

"Look, let's be honest, he clearly likes you." Undyne said, staring right at you, causing you to finally turn away from applying mascara.

"Undyne, I'm assuming Papyrus also told you that I got rejected last night?" You angrily hissed, worried about him hearing in case he was in his room next door.

"Oh please, I've seen the way he looks at you, even if you haven't. Also, you don't look like someone who _feels_ like they were rejected." She grinned, reaching one scaled hand out and twanging a lacy bra strap. You gasped, then you opened your mouth to protest, and then you closed it again, blushing furiously. "..Uh huh. Just what I thought. You're totally gonna seduce him, aren't you?" She was literally on the edge of her seat now, balling up your bed sheets in her fists.

"I can't believe Papyrus told you." You said, avoiding what she'd said.

"DEFLECTION!" Undyne shouted, jumping up and pointing straight at you, a wide grin on her face. Before she could speak again, you quickly covered her mouth with your hand and strained to hear if anyone was around.

"Okay, so maybe that was my plan. But no one knows. Payprus doesn't even know. He wouldn't understand, either. Don't tell anyone, okay?" You hissed quietly. She only grinned and nodded, causing your hand to move up and down in time with her movements. When you took your hand away, she squealed a little, and then calmed down. You went back to the mirror, trying to put the finishing touches to your outfit on.

"Everyone is coming you know. Mettaton's the best at parties. Even Asgore is there. Actually, I think even Burgerpants is coming!" She was speaking so fast it was hard to keep up. "Oh and Alphys is totally here right now she's just downstairs getting Mettaton drunk."

"Wait, what?!" You exclaimed. Images of Mettaton trying to drink alcohol and breaking himself flashed before your eyes. After taking one last look in the mirror and deciding that you were as ready as you'd ever be, you rushed downstairs.

When you reached your kitchen, you gasped for two reasons. Firstly, because the room looked better than you had ever seen it. Mettaton had really gone to town on the decorations. There was glitter and bright banners everywhere, as well as balloons and a few party poppers. Over on the counter, he had tastefully lined up all of the alcohol that you owned - altogether it was far too much for the amount of people you thought would be coming. Secondly, you gasped because there, on your dining table, Alphys was straddling a very still Mettaton.

"Alphys?" You could only say her name, completely confused as to what you were looking at. Upon hearing her name, you jumped a little and looked up at you.

"Don't worry." She smiled shyly, before looking back down at Mettaton's open chest panel and began fiddling around again.

"Alphys, what are you doing? Undyne told me you were getting Mettaton drunk...?" The more you spoke, the more stupid you sounded continuing this conversation. With her back still turned towards you, Alphys laughed a little. You heard a small zap, then she shut his panel and jumped down off your table.

"I'm just re-wiring him a little so that he'll have an experience similar to getting drunk. Actually, it'll grow stronger and stronger over time too, just like consuming real alcohol." She explained, hands sheepishly in her pockets. "I'll turn him back on when people start arriving."

You moved over to the powered-down robot cautiously. You had never seen him turned off before and it felt odd to be looking at him now. It felt almost like you were watching him sleep, and decided to try and check out the rest of the house before everyone arrived.

Walking round your house, you became more and more grateful for Mettaton's efforts. Whilst you had gotten ready, Mettaton had thoroughly cleaned every surface in the house and had stuck different banners, signs, and trinkets everywhere. Countless small objects like glass animals and tiny statues were placed on every surface, before being coated in glitter. By the end of the night, you could just tell your hair, your clothes, and your lungs would be full of the stuff.

You heard a doorbell ring. The party was about to start.

**Notes for the Chapter:**

> Hope you enjoyed! Free free to leave any comments and questions on here, or you can send me asks on my tumblr - underblogger.tumblr.com :) Next chapter should come soon!!


	3. The King Chugs Beer

**Summary for the Chapter:**

> Let's get this party started! Who knows what'll happen, eh? ;)

The king of monsters was the last person you expected to open the door to.

"Your Majesty!" You brightly exclaimed as you swung your door open, grinning nervously. Asgore only chuckled and held up a crate of beer. The image was so odd it was almost laughable.

"Please, I always say this, do just call me Asgore! I've brought some drinks, is that alright?" Asgore asked, handing you the heavy crate whilst he took his purple coat off and hung it up on a hook next to your door. Your impression of him only got stranger as you realised the king of monsters was wearing a custom-made pair of black jeans and a blue woollen jumper.

"Sure, Asgore. Drinks are being kept in the kitchen for now!" You brightly said, walking with him to your kitchen, still straining with the heavy crate. However, the second you placed it down Asgore immediately got a beer out of it, the can hilariously small in his hand. He squeezed the can slightly and it burst open, the froth coating his fingers, before downing the whole can. You only stared in stunned silence, but the rest of the room cheered.

Introducing your monster friends to alcohol had been an interesting experience at first. A lot of them had started off with a very low tolerance, which had also led to introducing your monster friends to what a hangover was. However, they had taken to it well, and some of your taller friends like Undyne and Asgore had very high tolerances. This was also currently being proved by the king himself, who was already taking another beer out of his crate. You turned to see Undyne madly cackling and cheering for Asgore to chug it. How had it gotten to this already? Sighing, you saw the king down another can in exactly the same fashion, spilling more foam on himself in the process.

When you heard the doorbell ring, you were eager to leave this bizarre scenario behind and quickly left to answer it. Strangely, when you got there you realised they had already started to open the door.

"HUMAN!" You heard Papyrus cry. Confused, you could only watch as Papryus came balling in, with Toriel shyly following behind him.

"Papyrus? Weren't you upstairs? Why did you ring the doorbell? This is your house!" You stuttered.

Papyrus smiled at you. "HUMAN, I WALKED TORIEL HERE!" Behind him, Toriel was chuckling and carrying a rather large bottle of wine. Clearly, no one thought to tell the guests that you were providing the alcohol. It probably hadn't entered Mettaton's mind.

"Hi, Toriel." You laughed, taking the bottle from her. "I'll go put this with the rest, please do come in!" As you went and placed the wine on the counter, you heard a buzzing start up and turned to see Alphys working on Mettaton again, probably re-activating him.

"Hey, guys, I'm going to go to the living room and put some music on, okay?" You said to your guests, who nodded and smiled at you in return. Your living room was the largest room in the house, and had loads of room to dance in. Putting your typical party playlist on, you could only laugh whilst imagining your friends ever listening to popular dance music - but there was nothing else you could think of playing. As soon as you got music going, Undyne darted into the room.

"We can talk now, no one will hear us." She excitedly said, leaning towards you.

"Oh, god..." You said, worried about what she wanted to say.

"You look great. I'm gonna go to Sans' room and get him. You can do this."

"Undyne, you don't need to - "

"No! Shush! I'll help you in any way you can!" She squealed before darting up your stairs.

As soon as she'd gone, the nerves began. The first impression you made on him tonight could make or break your plan. It all rested on the moment he saw you, as you hadn't seen him since last night. It was all too much. You needed a drink. Moving through to the kitchen and grabbing yourself a cider, you thirstily opened it and immediately started drinking. You realised that in the short time you'd not been paying attention, Burgerpants, three Temmies, and Muffet had arrived. Muffet already had a small jug in her hand - presumably drinking an alcoholic spider cider.

"HUMAN!" Papyrus half-yelled next to you, nearly causing you to choke. "CAN I HAVE A DRINK?"

"Umm..." You didn't know if Sans would be happy with Papyrus drinking or not, actually. You hadn't actually seen Papyrus drinking before, but that didn't mean he had never drank. "You should ask Sans!" You called back, straining to be heard of the sound of the music in the next room. Upon hearing you, Papyrus only nodded and sped out of the room.

It was at this point that you saw Undyne appear at the door to your kitchen, waving madly at you and grinning like a maniac. Anxious, you quickly walked over to Asgore, who was talking to Alphys about something sciencey. They didn't really notice you were there and kept talking. You weren't paying any attention. You were far more concerned with Sans coming into the room. You nodded at something Alphys said. You laughed meekly at a terrible joke from Asgore. Still no Sans. You could feel the pit of your stomach twisting and lurching with nerves. Alphys had moved on to anime. She was telling Asgore about something new she was watching.

Your heart suddenly stopped. Sans had walked into the room.

Wanting to look like you hadn't been waiting for him, you turned to Alphys. "So Alphys, are they going to make a Mew Mew Kissy Cutie 3?" Alphys snorted in response. Out of the corner of your eye, you could see Sans going over to the drinks. You'd bought his favourite whiskey for him.

"I doubt it. Not after the disaster of Mew Mew Kissy Cutie 2!" She said, clearly ready to launch into another rant about how terrible it was. You felt a hand on your shoulder.

"Hey babe, looks like you're out of wine there!" Undyne said over your shoulder, a hint of mischief in her voice. "We'll go get you another?" She suggested. However, she didn't wait for an answer and simply took the glass out of Alphys' hand, dragging you away with her. You were confused until you realised that Sans was still nearby the drinks.

 _Oh no_.

"Undyne, wait, stop - " You hissed desperately, before being cut off.

"Which wine was she drinking?" Undyne asked you, loudly. She was stood between you and Sans, but it was still nerve-racking. The plan suddenly seemed like a very bad idea.

"Uh - I think she was on the rosé." You squeaked. Undyne rolled her eyes, hearing the nervousness in your voice.

"Pull yourself together." She whispered to you, before stepping slightly away from you. If Sans looked to his right now, he'd look right at you. "Will you reach it for me? It's at the back." She declared, at the same volume as before.

You blushed furiously and shook your head, but upon seeing her angrily glare at you, you quickly turned around. The bottle was the farthest away in the whole group of wines. Knowing exactly what Undyne was trying to get you to do, you leant slowly over the counter, reaching your arm out for the bottle. You ended up on the balls of your feet, fully bent over. You didn't dare look, but in your peripheral vision you swore you saw your skeleton crush staring at you.

"Thanks!" Undyne grinned when you passed her the bottle. She poured the drink easily, before running off giggling. Still not daring to look at Sans, you chose a route out of the room that you knew would be in his line of sight, and made sure you swung your hips as much as possible as you walked away.

**Notes for the Chapter:**

> As ever, thanks for reading!  
> Don't be shy to leave any comments below or send me an ask on my tumblr - underblogger.tumblr.com :)


	4. Clearly, Getting Robots 'Drunk' Is Always A Bad Plan

**Notes for the Chapter:**

> This chapter is a little longer than usual, do tell me if you prefer it when I post more at once!  
> This was extremely fun for me to write ;)

"Hey, how many drinks have you had?" Undyne called to you over the music and the crowd in your living room as you both danced. Trying to think of an answer for her only made you giggle, because you weren't entirely sure.

"Some!" You winked, before continuing to dance.

"Yeah, thought it would be a lot." Undyne laughed. "You know, if you keep dancing like that I think you'll catch someone's attention..."

As Undyne talking became background noise to you, you swelled with pride and confidence. Clearly, your plan was working, and the thought of driving Sans crazy with wanting only made you cackle with glee. With alcohol fuelling your energy and the bass fuelling your dance moves, you began to lose yourself in the music.

"Hey." Undyne said, grabbing your shoulder to get your attention. Frowning, you stopped dancing and turned towards her. "You aren't seducing the right person, stupid!"

Your heart stopped.  If Undyne wasn't talking about Sans, then who...?

"OH, DARLING!" Someone called behind you. Part of you wanted to slap yourself in the face with frustration. As your turned around, your fears came true - Mettaton was stood right behind you, beaming.

"Hey!" You exclaimed brightly, trying to subtly look around to see if Sans was in the room. You couldn't see him.

"You look... wonderful. Fabulous. Amazing." The robot purred as he put a hand on your waist to steady himself.

"Hey, are you okay?" You asked. Mettaton was swaying alarmingly, as well as the fact that he was leaning very close to you.

"I've never been better, darling. Clearly, neither have you with _that_ dress on." Mettaton winked. The alcohol fuelling your system caused you to only blink with surprise.

With another alarming sway, Mettaton pushed you backwards into a wall, with one gloved hand steadying himself on the wall and the other holding your waist. You were trapped here now, between his arms. Looking around, you couldn't see Alphys, and Undyne was too busy laughing with Papyrus for either of them to help you. Mettaton's hand slowly slid from your waist to behind your back, pulling you closer to him.

"Burgerpants talks about you a lot." He chuckled in your ear. You laughed politely, but didn't really know how to respond.

"Um, are you allowed to call your employees names like that?" You asked. The TV star dramatically waved a hand in the air, dismissing what you'd said.

"Everyone calls him that. _You_ call him that. Does that mean you're _as bad as me_?" Mettaton smirked. He moved in closer to you - as if that was possible - and you placed a hand on his chest plate, steadying yourself. It was hard to breathe with your face practically pressed against him. In the dim light, his perfectly crafted features held an expression of pure confidence - this was the only time that you could see a 'bad boy' side of Mettaton, if it even existed. You hadn't expected to get this kind of attention from him, and the drunken part of you kind of wanted to go with it. However, the discomfort of how close he was sobered you slightly and you remembered the whole reason you'd held this party. _Sans._

"Hey, Mettaton, I've run out of cider!" You suddenly exclaimed. You shook your half full can in your free hand, hoping he wouldn't hear the sloshing, and smiled innocently. You could see the robot processing what you've just said, before he stepped backwards.

"Go get another." He winked. You'd never darted out of a room so fast, your mind racing with what had just happened. You quickly made your way through the dancing crowd and made it into the hall, panting slightly _. No time to stop, though. Mettaton could decide to follow you._ Powering forward, you pushed past two Temmies in your hall, swept past Asgore in your kitchen doorway... before crashing straight into someone.

"Hey, hey! Watch it!" A deep voice blurted drunkenly. Whoever you'd collided with had caught you carefully in their arms. You looked up, only to see that you just crashed straight into Sans. He looked down at you for a second, before making a similar realisation. "Oh. _Hey._ " He added, his expression unreadable.

"Sorry. Hey. Didn't mean to do that." Your voice sounded a lot more confident and nonchalant than you actually felt, and you were proud of yourself for that. It was at this point that you realised this was the first time you had actually spoken to him since he rejected you. This had to look good. Sans chuckled a little and leant forward, dropping his arms from around you.

"Where have you got to go so fast, eh?" He asked, taking a large gulp of whiskey.

"I need more alcohol!" You smiled. The feeling of how hard you were trying to impress him and how fake your smile was made you cringe slightly.

Sans stared into your eyes. Worried that he could tell you were lying about the alcohol, you gently reached up and took his whiskey from him.

"Now I have some though, don't I?" You sweetly smiled at him, before taking a sip. Unfortunately, in the midst of trying to look cool in front of him you'd forgotten just how strong this whiskey actually was. Struggling to keep a calm expression, you wore more of a grimace than a smile as it burned your throat all the way down.

"Heheheh. Guess you do." He grinned. Happy with how well that had just gone, you winked at him.

"I'm going to go dance. You should join me!" You smiled, innocently.

"I need a new drink first, kiddo." He drawled. Sensing that was the best you'd get from him, you turned around to walk away - and saw Alphys stood in front of you.

"Alphys?" You exclaimed, startled. _When had she gotten there?_

There was a small pause between you as Muffet pushed past, giggling.

"Hey, actually, do you want to dance?" You asked Alphys. She looked confused for a second, but grinned and nodded.

-

Right at the height of your favourite song, Alphys leaned closer to you to whisper in your ear.

" _He's_ behind you. Go for it." She hissed. You wanted to know how Alphys knew what was going on, but now wasn't the time to care.

Wiggling your hips, you danced as sexily as you could manage. Every fibre of your being was on fire, the feeling of being drunk and trying hard to impress coursing through you to create an energy that you never knew you had. After a while, you ran your hand through your hair and took a peek behind you. Around 3 meters away, behind a few dancers, Sans was leant against a wall, staring right at you. You decided to get brave. Placing the fire whiskey down, you turned to Undyne and Alphys.

"Hey, do you guys know what a slut drop is?" You asked. They both laughed incredulously.

"I have no idea, but do whatever you need to do to get his attention. We'll stay for a little while, but we'll leave if we think he's going to come over." Undyne assured you.

That was all you needed her to say. Slowly, you started rhythmically swinging your hips in a circle, before slowly dropping to the floor. Your thighs burned a little from the strain, but confidence saw you through. Once on the floor, you slowly pushed your bum out as you straightened your legs, then your back, and finally brought your head up. Undyne and Alphys had left.

You barely had time to realise what that meant before you felt a thin, bony hand rest on your shoulder from behind. Excitement pulsed through you.

"You've got moves, kid." A deep voice whispered in your ear. You could feel his presence behind you, the excitement causing heat to burn within you.

"Were you watching me?" You asked devilishly, turning to face him.

"Is that what you wanted me to do?" He retorted, not missing a beat.

"That didn't answer my question!" You grinned, bring a hand up to rest on his shoulder.

"Answer one of mine and maybe I'll answer it."

"Go on?"

"Do you like flirting with robots?"

Your heart skipped a beat. Taking your hand off his shoulder, you struggled to think of something to say. Clearly, he'd seen you talking to Mettaton earlier. Embarrassment and frustration washed over you, causing a bright red blush to burn on your cheeks.

"I... uh... what are you talking about?" You stuttered. Sans laughed at you in response.

"Oh, feigning innocence?" He smirked, before leaning in close to you. "Does that mean you're _as bad as him?_ "

His mockery was even more embarrassing. Worse still was how bad it must've looked - Mettaton stood over you, pushing you against a wall, arms around you...

"Woah, wait." You suddenly said, realising something. "Weren't you in the kitchen _straight after that?_ How do you even know that happened?" Sans gulped slightly and drew back, a look of panic crossing over his face before it was replaced with a calculated, cool expression.

"Uh, Papyrus told me 'bout it." He stuttered quickly. "But, was that an admittance?" His eyes gleamed. He'd caught you out.

"Okay." You confessed. "Mettaton came onto me. Are you jealous?" You winked.

"Ah ah ah." He swiftly said, waggling a bony finger at you. "That's a second question."

"Fine." You sighed, "Answer my first one."

Sans shrugged. "Sure, I was watching."

"Liked what you saw?" You eagerly pressed.

"Nah, it's my turn to ask something. Did you plan for me to come over to you?"

Before you could think of something clever to reply with, you heard a loud gasp. Turning to your left, you saw an excited, drunk Mettaton making his way over to you.

"DARLING!" He cried. "You're BACK!" He clapped his gloved hands together in delight. Next to you, Sans chuckled softly and lazily rested an arm around your shoulders.

"Um, hey Mettaton!" You meekly said, wishing he would go away. Sans' arm seemed to radiate heat onto you even though it was just bones. You couldn't stop thinking about the physical contact.

"Oh Darling, I was looking for you. Do you want to dance, beautiful?" He smiled, holding a hand out to you.

"Hey, she's still with me right now." Sans suddenly declared, swiping his hand away. "You can have her in a few minutes."

Mettaton looked at Sans as if he hadn't noticed him before. "Oh, Sans. Hello." He curtly said. "Look, this _gorgeous_ creature and I have some unfinished business. I'm sure you understand." Something in his voice was hostile, but also eager. You knew Mettaton lived off drama - you had to try and diffuse this.

"Hey Mettaton, actually - "

"Look buddy." Sans cut you off abruptly. "You can't just walk in on a conversation and pull someone out of it because you're famous and you feel entitled." He growled. Something in your stomach clenched, noticing Sans' eye sockets were cold, dark and empty. His grip on your shoulder tightened, and he pulled you away from the robot's reach.

"Sans - "

"Oh, is a certain someone a little jealous? Can't contain yourself in a _true star's presence_?" Mettaton gloated, gesturing arrogantly to himself. Clearly, no one was willing to let you talk. However, as soon as Mettaton had said the word 'jealous', you realised how much that word characterized Sans' current behaviour.

"Jealous? Of you? _Please_." Sans snorted. "You thought humans ate glitter."

"I have several TV shows, an acting and musical career, and possess my own resort."

"I have dignity."

"GUYS!" You finally managed to shout over them. Shocked at hearing you speak again, they both turned to look at you. "You're both drunk. I wanted to have a good time." Holding your face in your hands and looking at your feet, frustration bubbled inside you. The cheerful, flirty mood you were in before had been ruined, their argument having left a sour taste in your mouth. Being wanted was fun, but not when they had gotten so aggressive. This was not what you'd planned at all. After a short few seconds, you looked up again to see that Sans and Mettaton both looked concerned.

"Look, Mettaton." You began. "Go find Alphys and get sober again - if you'd had real alcohol I'd be making you down pints of water right now. And Sans..." You trailed off as Mettaton staggered away. You wanted the skeleton to stay, but his argument with the robot had clearly riled him up.

"Yes?" He quietly said. If you didn't know Sans, you might've been scared right now. His usual grin was twisted into more of a grimace, teeth grinding viciously against each other, and his eye sockets were empty, hollow, dark pits.

"Go calm down." At your words, he visibly deflated and turned away. The feeling of wanting suddenly gripped you and you grabbed his arm. "Come back after, though? I'll probably be here or in my room, it's pretty late." He turned to nod at you, before leaving.

The second the two had left, Undyne appeared at your side.

"What just happened?" She asked, placing a comforting hand on your shoulder. You sighed, gently.

"Go get Papyrus to calm Sans down, then meet me in my room. It's too loud to tell you here." She nodded at your words and swiftly left.

-

"...and that's when you came over." You finished, roughly running a hand through your hair and glancing nervously at Undyne, who held an intense expression. By now, you felt completely sober again - you hadn't had much alcohol since the argument.

"Jeez. That's really not what I expected to happen." Undyne paused, looking down at you. "Cleary, it's not what you expected either." It took a while moving past guests while climbing the stairs, but at last she managed to deposit you at your bedroom door.

"No, but on the plus side, there was some major flirting going on before it happened." You grinned. She chuckled slightly before lightly punching you in the shoulder.

"Yeah, he looked pretty jealous, too." She winked, laughing. "Go to bed. I'll be sleeping on your sofa, with Alphys." You only nodded, turning to crash into your bedroom door.

"Wait, hey!" She suddenly said. "I'll sort out the guests who are still here. Whoever needs a bed will get one, so don't worry about it."

"Thanks bestie!" You smiled.

Being back in your room was strange, after the night's events. On one hand, you'd made some pretty good progress with the whole situation, considering Sans had definitely stared at you at least once tonight - and wasn't all that good at hiding it - but on the other hand, you didn't know if Mettaton had put him off.

You let out a long breath as you looked at yourself in the mirror. Thankfully, your makeup had faired pretty well over the course of the night - you looked pretty much just like you'd set out partying like earlier this evening. Your room was dimly lit, only from your bedside lamp, and it was dark enough to make you feel tired. It was probably time to go to bed. Slowly, you reached up and started unzipping your dress -

"Ah, going for another naked run?" A deep voice chuckled, freezing you in place. Glancing over to the door, you saw a smug Sans stood grinning, hands in the pockets of his black jeans. "I wouldn't advise it with so many people in your house." A thousand swear words came to mind - you'd completely forgotten you'd told Sans to visit you again, and now you were stuck with your dress undone, unable to zip it back up.

"Wha - when did you get in here?!" You gasped, clutching the loose fabric to your chest.

"Just now. Y'know, if you do feel like gettin' naked I'm not stopping you." He drawled, not even trying to hide the way his eyes scoured every inch of your body. You realised, with some trepidation, that as the material peeled from your shoulders, it began to reveal the lacy bra straps to the bra you'd put on to impress Sans. Nervousness filled you, but you tried to play it cool.

"That's just what you'd want, isn't it? I was getting into my PJs." You nonchalantly remarked.

"From the looks of your... _attire_... it's clearly something you considered too." Sans pointedly stared at your bra straps, his grin growing ever wider. You couldn't help blushing.

"You can never keep your eyes off me, can you?" You winked.

"Not when you look like _that_."

"Care to explain what _'that'_ means?"

Something beeped, a short, high pitched sound. Sans looked down into his pocket, before making a small 'oh' noise.

"It's time to read Pap his story." He announced, with reluctance. "I'll let you get naked, eh? I hope you won't be _bonely_ without me." He joked, before disappearing out of your door.

**Notes for the Chapter:**

> Thanks for reading! Do tell me what you thought in the comments below, or send an ask to my tumblr on underblogger.tumblr.com :)


	5. It Begins

**Summary for the Chapter:**

> Oh MAN you would not believe how excited I was to write this chapter - and how excited I am to keep writing this.

Waking up with a hangover was definitely the worst part about drinking. However, you were determined to push past it for the sake of the countless guests sleeping downstairs right now, and forced yourself out of bed.

"Oh, god." You involuntarily groaned as the ache of a night of dancing and the cold of your room hit you full blast. Food was the only thing on your mind right now,  you didn't even care that your pyjamas only consisted of a pair of tiny black shorts and a thin tank top.

The kitchen wasn't much warmer than your room, and you regretted not getting dressed properly as the cold floor seemed to seep right up your legs to chill you to the bone. For a moment, you thought about simply pouring yourself some cereal, but felt guilty when you realised it wouldn't be long before you had a whole group of hungry, hung-over guests that would also want breakfast. With that in mind, you pulled out some pots, pans, and started searching for sausages and bacon.

"HUMAN!" Papyrus cried, causing you to chuckle involuntarily. It was like cooking food was a magic key to summon him. "YOU ARE COOKING!"

"Morning, Pap." You lazily smiled at him. "Sleep well?"

"I SLEPT VERY WELL, THANK YOU!" He paused for a second, and his usual grin wavered.

"Papyrus?" You worriedly questioned, walking over to him. "Are you okay?" The colour returned to his face and he smiled at you weakly, shaking his head.

"I AM... I am just a little queasy." He admitted, holding a skeletal hand over his mouth. Clearly, Papyrus had ended up drinking last night after all.

"Oh, join the club." You laughed. "Try drinking some water, it might help. Do you want to help me make breakfast for everyone?" Your skeletal friend nodded gratefully at you, before immediately pouring and drinking a whole pint of water. Sometimes, Papyrus truly amazed you.

Cooking with him was fun. You cracked jokes, told each other bizarre stories from the night before, and discussed your plans for the day as you fried up a ridiculous amount of food. Of course, there were a few times that you had to quickly turn the heat down on Papyrus' half of the stove - for fear of him setting the house on fire - but for the most part, your food remained unburnt.

"Are you c-cooking?" A weak voice piped up as you started laying breakfast on the table. You looked up to see Alphys, wearing her usual lab coat, stood in your doorway.

"Yeah, Pap and I have made breakfast for everyone." You paused, eyeing the sheer volume of food that you had made. "I... I'm realising I don't actually know how many people have stayed over. Is this too much?" You nervously added.

"It's probably just the right amount." She replied, thoughtfully. From the expression on her face, she was probably trying to actually calculate how much food should've been made.

"Can you go and fetch the others?" You asked, a little breathlessly as you lifted a particularly heavy bowl up. Alphys seemed to snap out of a trance, and nodded shyly as she rushed out of the room.

It wasn't long before your kitchen was packed with party-goers from the night before. All in all, sat around the table was you, Papyrus, Alphys, Undyne, Asgore, Toriel and Sans, who had cheekily eyed you up before sitting next to you.

"SO," Papyrus suddenly exclaimed, halfway through the meal. "WHAT IS EVERYONE PLANNING ON DOING TODAY?"

"Well, my job never ends! I'm still working with the leaders of the human world on monster rights. Tori is striving to improve monster/human relations, too." He briefly beamed at her. "We make an excellent team." She frowned a little, but didn't dispute it.

"I... er... I always have science to do! And anime to watch..." Alphys smiled, receiving an affection pat from Undyne next to her.

"And I always have guards to train! Well, I mean, less so now that we're on the surface, but I still have my job to do." Undyne rambled slightly, whilst eagerly eating slice after slice of bacon.

"I have 101 jobs." Sans stated, solemnly. There was a moment of silence when everyone a the table took him seriously and stopped eating to stare, before he burst out laughing. "I'm kidding. _Tibia honest_ , I don't have that many." He chuckled.

"NOT THE PUNS!" Papyrus groaned, holding his head in his hands. Eyes at the table turned towards you.

"Well, I mean, It's Sunday - so I don't have work or anything today!" You said, a little guilty. Everyone else seemed incredibly busy compared to you. "I mean, there's probably a lot of tidying up to do today, though." You added, as an afterthought.

"HUMAN! YOU MUST NOT DO THIS TASK ALONE! I, THE GREAT PAPYRUS, WILL HELP YOU!" Papyrus loudly announced.

It didn't take long for your guests to slowly trickle out of your door after breakfast, each person clearly busy with other things to do, but still eager to thank you for a good time. You promised them you'd hold another party, and soon. Sans disappeared at some point during your goodbyes, but you weren't sure exactly what time he'd left. Spending the day tidying with Papyrus turned out to be more fun than expected - you spent a lot of time cracking jokes, giving each other puzzles to solve, and having long breaks in which you ate spaghetti and listened to some new tracks from Napstablook. However, the amount of decorations that Mettaton had put up yesterday weren't easy to take down - as well as a LOT of burst beer cans that were littering the floor - so it was getting dark by the time you finished.

"HUMAN!" Papyrus loudly said as the last piece of rubbish had been thrown away, "NOW THAT WE ARE FINISHED I MUST LEAVE YOU, TO GO AND SEE UNDYNE!"

"Sure, do you know what time you'll be back?" You asked, watching him choose from 3 pairs of shoes, all the same size, colour and style.

"I THINK THAT I WILL PROBABLY BE STAYING OVER! WE HAVE A LOT TO DISCUSS, AND A LOT TO COOK!" He grinned. The prospect of Papyrus and Undyne cooking together all night brought a shudder up your spine, but you still wanted him to have fun.

"Well, ring me at some point, okay?" You asked. He only nodded and practically ran out of the door with excitement.

"Well, looks like it's just me tonight." You sighed, as you gently shut the door.

"Is it?" A low voice said behind you, making you jump out of your skin. Quickly spinning round, you saw Sans stood there, looking smug _. How did he always manage to creep up on you like that?_ "Hey, if Pap is out, we may as well do something too. Wanna watch a movie?" He drawled, hands in pockets, smirk plastered all over his face. Your heart went straight to your mouth. _A night alone with Sans, watching movies? Yes please._

"Yeah, sounds great!" You smiled, trying not to sound too eager and failing. Sans chuckled at your response, before gesturing to your living room with his head.

"Come on, I've got the perfect film for you." He smiled.

-

You'd ended up sat together on the loveseat, in the dark. Even though you were sat half a foot away from him, every part of you wanted to creep closer, to be nearer to him, to be in his arms. However, thoughts like these brought an embarrassing blush to your cheeks - thank god it was so dark in here.

"I hope you like horror." Sans said as he switched on the TV. You recognised the film as something that had just come out, and was well known for being very scary. Unfortunately, whilst you weren't a wimp, you weren't exactly the bravest person in existence either.

"I'll be fine..." You nervously whispered, as the opening credits came on.

It didn't take long for you to get scared. the film was jam-packed with images of possessed girls, devils, hauntings, and a lot of gore. It definitely wasn't something you would have chosen of your own accord. On the first jump scare, you screamed, and got laughed at by Sans. On the second, you grabbed him without thinking.

"Woah." He said, gently catching you. "Too much for ya?" He drawled.

"Oh, sorry." You blushed, slowly moving back to your seat. "I'm fine. Honest."

 As the paranormal film neared its climax, the tension started to get to you. Without realising it, you'd been inching closer and closer to Sans as your nervousness started building. A devil appeared on the screen and you leapt towards him, balling up his shirt in your fists. He didn't laugh at you this time, only wrapping his skeletal arms gently around you, resting his head in your hair. He smelt of museums, the smell that comes from quickly flicking through old books. It was an addictive scent that only caused you to try and snuggle into him further. By the time the end credits rolled, you had your head buried in his chest, with his arms wrapped tightly around you. Silence fell as the movie ended.

"So," He gently said after a long pause. "Guess you don't like horror, huh?"

"That was a very scary one." You mumbled into his shirt. He chuckled, and you looked up to see him staring rather affectionately down at you.

"If you think that's scary, you should see this other one I know."

"Oh no, I couldn't take another!"

"It's okay, I'm here with you, right?" You blushed at his comment and looked away to try and hide it. "I'll take that as a yes, then." He smiled, as another movie's title came onto the screen in blood red letters.

This time, you didn't move back to your side of the sofa and Sans didn't remove his arms from around you. The whole time, you were either sat comfortably in his arms or cowering into his shirt, your eyes shut tight against his ribcage. It was heavenly, being so close to him for such a long time.

Towards the end of the film, however, you started to notice his hands moving from around you. Slowly, one of his hands started rubbing up and down your waist, from just below your hip to just under your breast. His other hand rested, still, on the bottom of your ribcage, phalanges splaying out across your stomach. As you noticed this, you subtly responded by laying one hand on his shoulder whilst the other played gently in-between his ribs. Once you coaxed a gasp from him, that was it. It became a game to see who could push the other's buttons enough to get them to make a noise. By the time the end credits rolled on the second film, you were no longer paying attention and he was breathing as heavily as you were. As silence fell, Sans gently used a single bony finger to lift your chin up to look at him.

"Wanna take this upstairs?" He drawled. Every part of your body felt like it was set on fire. You wanted to scream yes, and throw your arms around him. Although, you also remembered how harshly he rejected you and felt a little angry that you were just putty in his hands.

"What does _that_ mean?" You cheekily asked.

"It means," He began, sitting up to look at you properly, "that I want your company, and I'm pretty sure that you want mine." The smugness in his face only made you more angry. Slowly, you stood up and looked him directly in the eye, determined to make him see how you had felt that night.

" _Sorry_." You said, before starting to walk away. You didn't get two steps before he grabbed you by the wrist.

"Wait, hey, what? What are you doing?" Sans asked, confusion seeping into his voice, the cool act gone. After a long pause in which you didn't respond, Sans gently turned you around to face him.

"I see." He said after a little while, the confidence returning in his voice. "You trying to get me riled up, kiddo? You trying to tease me by dressing sexy and snuggling against me?" It was really hard not to blush, as he laid out your actions in front of you. Another pause followed, as he waited for a response that you didn't give. Shock had filled you to the core and stolen away any words that you might've otherwise said to him.

"The look on your face says it all." He growled, as he pulled you close, his face mere inches from yours. "If you wanna play this game, kid, let's play. You make me want you, I'll make you want me. You tease me, I'll tease you. I can make you beg. I can bring you to your knees. _Literally_." You gulped gently, the passion in his voice going straight to your crotch. You looked straight into his eyes.

"Game on, Sans."

**Notes for the Chapter:**

> Thanks for reading! Feel free to leave comments below or send me an ask on my tumblr - underblogger.tumblr.com :)


	6. Guess who makes the first move?

**Notes for the Chapter:**

> Maaaaaaan this was so much fun to write. Also, I will get round to replying to your comments asap, I loved them all so much! It's great when you guys are just as excited as I am!

You woke up the next morning with light spilling into your room through open curtains. By the time you'd dramatically swept away and up to your room last night, you'd been so exhausted from the adrenaline rush that you'd gone straight to sleep, and clearly hadn't even bothered to close your curtains. Your alarm clock told that you that it was 11AM. Ugh. You'd overslept. It was also at this point that you realised you'd skipped pyjamas and was completely naked.

Below you, you could hear the clatter of people up too early making too much noise in the kitchen. It sounded like they were bashing all of your pots and pans together whilst yelling at each other. Clearly, Undyne and Papyrus had moved over to your house to make an unknown racket here, instead of at her house. Although you shared this house with the two skeleton brothers, most days were spent with your friends round at the house anyway. Slowly heaving your heavy body out of bed, you knew that the second you went for a shower someone would want your attention - so if you could sneak one now, it might even be long and leisurely.

Not wanting to repeat the mistakes you'd made earlier in the week, you began gathering any random clothes that you could throw on when you were clean. Jeans - check, Tshirt - check, socks - check... wait.

_Why was your underwear drawer empty?_

Not a single bra or pair of pants was where they should be. In fact, looking around your room, even the dirty ones that you'd cast on the floor days ago and never picked up were gone. All of your underwear was gone. Looking back in your empty drawer, you realised there was a little note taped to the back of the drawer. Frowning, you pulled it off its tape and began to read.

**Got no undies?**

**Remember, you started this.**

"Fuck." You swore under your breath. You easily recognised the handwriting as Sans', from the notes he and Papyrus left on his various messes round the house. So, he'd taken all of your underwear. What on earth were you going to wear?! Angry, you realised he'd even stolen the underwear you had been wearing yesterday. Was that... impressive?

The thudding of someone very loud and careless rattled up your stairs. Panicking, you realised Undyne was about to storm into your room and you were stood there naked in front on an empty underwear drawer. Dropping the note quickly, you turned and leapt into bed at a speed you didn't know you were capable of.

"WAKEY WAKEY!" She yelled as she kicked the door open. You sighed with relief - a second later and you would never have lived that down.

"Undyne... I'm in bed..." You weakly mumbled, trying to get her to go away. However, she was clearly having none of it and only moved further into the room. She stared down at you, intimidatingly.

"Then get out of bed! Pap and I are taking you out for a meal! Italian! Chinese! Afternoon tea! Thai!"

As Undyne continued to shout a list of things that you might eat, you tried to think of any excuse that would mean she would leave without realising what was going on. The last thing you needed was Undyne knowing how your relationship with Sans had developed. Subtlety wasn't exactly her forte, after all.

"HEY!" She suddenly shouted, snapped her fingers in your face. "If you don't get out of bed THIS SECOND, I'll drag you out!" Every thought in your brain was just internal screaming.

"No, wait!" You cried. You had to say something. Anything. "I'm naked!"

Undyne's face showed surprise, then disbelief, and then amusement.

"I'll get you some clothes then. Sure you aren't hiding someone else in there whilst you're naked?" She winked.

"No." You grumbled. These jokes were going to go on for a long time, knowing Undyne. You watched her busy herself around your room, grabbing items of clothing from a mixture of your floor and your wardrobe, before throwing them in your face.

"There! Dress!" She commanded, not looking away. _Were you meant to just change here?_

Fumbling awkwardly, you slipped them on under your covers before clambering out of bed. Without your underwear, you felt very exposed and vulnerable. At this point, Undyne was casting the occasional glance towards Sans' room and snickering a little. Looking at her in annoyance, you remembered something else that had happened at the party.

"Hey, Undyne." You began. "How come Alphys knew what was going on, with Sans?" The smirk instantly disappeared from Undyne's face and she looked a little guilty.

"Yeah, uh, look, I'm sorry. I was drunk, and excited, and she's my girlfriend! I just, it just slipped out. Sorry." She looked so guilty that you couldn't stay mad at her. _After all_ , you supposed, _Alphys probably wasn't the type to gossip anyway._

"Food, then?" You suggested. Undyne gave you a look of delight and bounded out of the room. Every part of your outfit felt weird and wrong without underwear. Who knew jeans and button up shirt were so hard to wear without pants and a bra? Annoyance at what Sans had done flared up within you, but a part of you was also shamefully aroused. The fact that only you and Sans knew about what was going on was a little exciting. You spent a long few minutes just _wishing_ that the blush would leave your cheeks. It didn't.

As you finally turned to the door, you realised an item of clothing had been placed in your doorway. _Undyne didn't say anything, so this must not have been here when she left,_ you thought. A single tag had been placed on the black skirt.

**Wear me.**

Surprise and dread flew through you. _You couldn't wear a skirt without pants!_

From below you, you heard Undyne call your name. Adrenaline coursed through you at the thought of her coming up and seeing this. As well as her reaction, you also feared the kinds of things Sans would do if you didn't wear the skirt, considering what he'd done this morning.

Sighing under your breath, you quickly changed into the skirt and began walking downstairs.

-

The walk to the restaurant Papyrus had chosen was traumatic, to say the least. Thankfully, it wasn't windy, but walking around with no underwear in public was an experience you weren't likely to forget. Every person you passed, it felt like they knew that you were exposed. Every eye that met yours in passing, it felt like a look of knowledge, of shame. Undyne told you that you were meeting Sans there, and you only dreaded the smug look that you knew would be on his face.

"NGAHHH!!" Undyne yelled, somewhat dramatically, as she threw the door open. Naturally, Papyrus had chosen an Italian restaurant, and was already mumbling the word 'spaghetti' under his breath.

"THERE HE IS!" Your skeletal friend called out, as he pointed across the restaurant. You took a deep breath, trying to compose yourself, before looking over.

Sure enough, there was Sans, sat at a small booth in the corner. He was already looking over at your group when you saw him - but then again, so was most of the restaurant after Undyne's display. He lazily drew his eyes across the three of you, before his eyes met with yours and a large, toothy grin spread all over his face. _Bonehead._

"I've saved seats!" He brightly exclaimed as you walked over. Undyne and Papryus only grinned before sitting down with him, but as you moved to sit next to Undyne, on the opposite edge of the group to Sans, a bony hand took hold of yours. "You wanna sit next to me?" He drawled.

Seeing no point to arguing, you sat down. Carefully, you noticed him look down to eye up your skirt, before meeting your eyes and cackling softly. Clearly, he was taking this game very seriously - and you fully intended you get him back for this. At the back of your mind, tonnes of different ideas for revenge slowly formed.

"Can I take your order?" A musical voice enquired. You looked up to see a young waitress stood in front of your table, a small notebook clasped in her frail hands.

"SPAGHETTI!" Papyrus instantly cried. She looked a little puzzled.

"Sorry sir, do you know which spaghetti meal you want to order?" She stuttered, eyeing him up nervously.

"Get him the spaghetti bolognese." Sans said, politely. "And I'll have fries."

"You do know that's a side order, sir?" Her face only got more puzzled, and you felt a little sorry for her. When Sans nodded, she sighed gently, before writing it down.

"I'll have the spaghetti carbonara!" Undyne grinned at her. The waitress then turned to you. It was at this point you realised you'd been so busy thinking about Sans that you'd not looked at the menu.

"I'll.. I'll have that too." You quickly said, not wanting to hold anyone up. As soon as you'd finished ordering, the waitress quickly left, looking somewhat relieved.

The meal, as embarrassed as you felt, started fine. The food didn't take long to arrive and in fact, the meal you'd ordered was pretty tasty. You made a mental note of what it was, in case you could get Papyrus to make you some at a later date. However, about halfway through the meal, Sans' left hand disappeared under the table. You noticed it instantly and your breath hitched in your throat as you tried to act calm and keep on eating. Maybe you were just over thinki-

A skeletal hand gently stroked your thigh.

You could barely keep a straight face as humiliation, excitement and fear filled you to the core. You were sat at the table with your friends, in a restaurant full of strangers!

"Hey, _____, you okay?" Undyne asked, staring at you. "You look flushed."

"Um, my food is a little hot." You stuttered, trying to think of any excuse to get out of this.

"Oh." Undyne said, looking underwhelmed. "Then you should cut your food up, dummy!" As she spoke, the skeletal fingers crept further up your leg.

"I... Uh..." You gasped, trying to keep calm. "Yes. I will." This was stupid. You were terrible at keeping calm.

"Don't worry," Sans drawled next to you. "Mine's pretty hot too." He smirked, looking straight into your eyes. They practically screamed lust at you, the small points of light in his sockets dancing in the dim light of the booth. As Papyrus then moved on to tell Undyne a story you'd heard before, the stray hand left your leg. It was a little disappointing - almost like he'd set all this up for nothing.

Suddenly, the hand reappeared and yanked your skirt up, leaving you bare and exposed under the table.

"No!" You half yelled out of instinct. All eyes turned to you, shocked. _Shit_.

"HUMAN, DO YOU NOT LIKE MY STORY?" Papyrus asked, looking hurt.

"No! I mean, yes! I'm sorry Papyrus!" You blurted out, trying to save yourself after what you'd done. "I was just daydreaming! Please, ignore me, carry on!" Slowly, he nodded before cautiously continuing to talk. There were people all around you, but no one seemed to see what was going on - thank heavens Sans had chosen a corner booth. Desperate to cover yourself up, your hands went straight under the table to yank your skirt back down.

You were met with resistance. There, underneath the table, Sans had a firm grip that was holding your skirt up and keeping you naked and bare. You shot him a crazed, pleading glance, but he didn't relent. A gentle chuckle left his non-existent lips. Grabbing his hand in yours and your skirt in the other, you tried desperately to yank them apart. After a few seconds, you took a little rest and tried to shake your hair into place, your expression settling again. Time for a second try. This time, you managed to budge his hand - but didn't want to rip the skirt. You had to give in.

"Let go." You hissed. He laughed, gently.

" _Sorry_." He grinned. _Must that word plague your life_?!

"I'll do anything." You pleaded. His face lit up.

"I was hoping you'd say that. Spend the day with me and I'll let go." He whispered. You didn't have any real time to consider his offer, as Undyne and Papyrus could start paying attention to you at any moment. "Hey, can you really refuse? Seeing as you're _sans underwear_."

"Fine." You growled. He grinned smugly, before letting go. Your skirt, thankfully, fell neatly back into place.

"We're going to have fun. I have a lot to do today."

**Notes for the Chapter:**

> Thanks for reading! Don't forget - leave a comment below telling me what you thought, or send me an ask on my tumblr - underblogger.tumblr.com :)


	7. A 'Fun' Day Out

**Notes for the Chapter:**

> Sorry this took so long, it took me a while to write this! I've had a bit of a busy week.
> 
> Can you spot the references in this chapter? ;D

"Are you guys finished? Wanna split the bill?" Undyne's voice cut through the thick tension between you and Sans. She sounded confused, but also a little amused. Thank God she didn't know what had just gone on.

"Yeah, let's." Sans said, eagerly. Clearly, he was very ready to go about his day, now with you in tow.

As Undyne signalled to our waitress that we wanted to pay, Papyrus turned to Sans.

"SO, BROTHER." He began. "WHAT ARE YOU DOING TODAY?" Sans grinned, and looked at you out the corner of his eye. Nerves filled you as you waited for his answer - hopeful he wouldn't be doing anything _too_ physically demanding, considering your outfit.

"Well, I'm gonna work a shift at my hotdog stand, then pick something up from Alphys, and after that..." Sans trailed off to glance at you. "I'm sure I'll figure something out."

"What are you doing today?" You asked Papyrus, eager for the attention to stay away from the fact that you were now spending the day with Sans.

"UNDYNE AND I HAVE ROYAL GUARD DUTIES!" Papyrus chirped, happily. It was heart-warming to see that he clearly loved every aspect of his job. Next to him, Undyne grinned and gave him a friendly elbow to the ribs.

As the waitress came back over with your bill, a knot in your stomach tightened. As soon as you'd all paid, you'd have to stand up. You'd have to walk around. You'd have to spend a lot of time with Sans. All without your underwear. The thought was simultaneously terrifying and arousing; you had a dirty little secret with Sans. Lusty visions of him undressing you suddenly filled your brain, the restaurant around you fading out of view as you imagined sharing the most intimate of moments with him.

"You coming?" A deep voice chuckled. Sans was already stood up, pulling his usual blue jacket on, as he cheekily eyed you. _Oops_ , you thought as a blush filled your cheeks. _Did I drift off into a daydream for that long?_

"Uh, yes!" You smiled, slowly standing. Sans gave you a knowing look as you checked your skirt was in place, before leading you out of the door.

"First stop, hotdogs." He said, walking confidently down several alleyways.

"And... how long are we going to be there?" In front of you, Sans didn't turn around.

"One, maybe two hours. Not long."

_-_

It turned out to only be a few minutes of walking before you both stopped outside what looked like a garden shed round the back of your local bus station. Without speaking, your skeletal friend pulled a sleek, wooden stand on wheels out of the rotting doors. He then walked around twenty meters down the road, before setting it up with a sign above it.

"There should be a stool in there!" He called to you, pulling you out of your fascinated trance.

"Sure!" You replied, looking into the shed. It was gloomy, dark, and very smelly. Taking a deep breath, you quickly dived in to try and find the stool.

Once you were inside the shed, you realised that it was full of junk. Inside, there was what looked like a sentry station made out of cardboard, another station which was coated in several different condiments on the inside, a broken hi-tech machine, water-logged science textbooks, and several crosswords that someone had ruined by writing 'Z' in every box. However, there was definitely no stool in here.

"Having trouble?" A voice made you jump.

"Oh god!" You cried out, spinning round. When you realised it was just Sans, you chastised yourself for being so jumpy. "I can't find a stool in here." You said, defeated.

"Naw, there should be one!" He smiled, stepping inside with you. It was very tight, which meant Sans was pressed up against you as he craned his neck to look around. That same scent drifted back to you as he leant in closer, filling you with a sense of safety. After a few seconds, he made a noise of realisation and suddenly leant forward. You weren't expecting it, and the movement shoved you backwards, making you cry out as you fell towards a stack of books.

"Hey!" Sans called as he caught you, a skeletal hand closed firmly around your wrist. "Don't fall." He winked, pulling you back up.

"Thanks." You gratefully said, clutching onto him to keep your balance.

"S'ok. Who knows what I would've seen if your skirt flipped up, eh?" He chuckled dirtily.

"Hey!" You laughed, gently slapping him on the shoulder. For a few minutes, you'd actually forgotten about your nakedness.

With a grunt, Sans gently leaned around you and pulled a leather-padded metal stool from underneath a plank of wood. He stood completely still for a few seconds, clearly waiting for the pile of junk to fall apart, but it held steady. When you both finally walked back to the hotdog stand, there was already a small girl stood waiting.

-

It took half an hour of both you and Sans serving hotdogs constantly for the street to quieten down. In a way, it was actually quite fun. You and Sans made a good team, swiftly moving around each other to load hotdogs up with different toppings and make sales. A few times, you'd bump into each other or reach for the same thing, and a small, sweet moment of contact would occur. After a while though, not used to standing up for so long without walking anywhere, your legs were really starting to ache.

"Wanna sit down?" Sans offered, after serving the last customer in the line.

"Yes, actually." You admitted, turning to hop on the stool. Stopping in your tracks, you suddenly became aware of your... outfit choices. If you sat on the stool, your skirt wasn't fully long enough to tuck fully underneath you. At the same time, it was too cold outside for you to take a layer off so that you could sit on it. Your options were either to sit bare on Sans' stool or freeze in the cold winter air.

"Here." Sans said behind you, after you'd been silently contemplating your dilemma for a few seconds. Gently pushing past you, he took his jacket off and laid it over the seat.

"What are you doing?" You asked, incredulously.

"Clearly, the leather wasn't an appealing option for you to sit on." He grinned, evilly. His eyes roamed obviously and suggestively down to your skirt, before lazily drifting back up to meet yours. When they did, they were full of lust and amusement.

"And you think that I'd want to sit on your jacket more?"

"I know what you'd like to sit on more." He moved closer to you, the pinpricks in his sockets fading a little, leaving him with dark, empty sockets. "Don't you?"

Your mouth was dry as his skeletal fingers stroked the bottom of your chin, keeping your head tilted up toward his. It was unbelievably arousing, how smooth he was. It was like he knew just what to say to turn you on.

"Cat got your tongue?" He asked, tilting his head to one side. Slowly, his left eye lit up with a round, bluey-yellow pupil. You'd never seen anything like it before.

"Your... your eye..." You whispered, staring at it. He chuckled at your shocked face, a deep and husky sound. His free hand slowly curled around you to grasp your bare bum, his skeletal fingers sending sparks all the way through your body. It felt like your very soul was on fire.

"It's a little secret of mine. I'm not like other monsters, ____. I can use my magic for things other than attacks. I can create... certain _body parts_." He explained, his voice thick with arousal and suggestion. His face was inches from yours. "Wanna see a little example?" You could only nod in response, fascinated.

Slowly, he opened his mouth and to reveal a slightly glowing, bright blue tongue. A small gasp left your lips at it's shocking colour, and his open mouth turned to a wide grin.

"It's... so blue." You said dumbly, staring at it. You couldn't help but wonder what it would be like to kiss him with that tongue. After a few short seconds, he closed his mouth again, before shrugging.

"Most of my magic has a blue colour naturally. That's why my eye looks blue as I'm doing it, too. It's a lot of effort to make it any other colour - 'cept maybe if it was invisible. Having no colour is much easier, but it would be a little weirder."

Your mind automatically went to thinking about his genitals. Clearly, even with magic, Sans was still lazy. _Would that mean his genitals would be that glowing blue colour too? Although, maybe if he's alone he wouldn't bother to make it a colour. What about if he was with somebody els-_

"Are you thinking about what I _think_ you're thinking about?" Sans laughed, cutting off your thoughts. _Crap. Was my expression obvious?_

"No!" You cried, embarrassed. "I was just thinking about... general magic." You huffed as you pulled away form him, absent-mindedly climbing onto the stool. It put a safe distance between the two of you. Shame was the only emotion you could feel as he nodded slowly, clearly not believing a word you'd said.

"Uh huh."

"I was!"

It was at this moment that a small girl coughed, drawing your attention to the job you were both supposed to be doing. Quickly and efficiently, Sans moved to serve her. It was interesting to watch him, as it was like he'd forgotten you were there - he'd moved so quickly into a friendly, business-like tone. After serving her, he turned and around and a familiar, smug grin spread across your face.

"What does that look mean?" You said, his face making you laugh a little. Sans' grin only got wider as he gestured towards you.

"Enjoying your seat?" He winked. The horror of realisation crashed through you. _You'd sat on San's jacket with no underwear._

"No!" You cried out, looking down at yourself. You pointed an angry finger at him. "You are washing this the second we get home!" Sans only laughed harder.

"I'm never washing it again." He wheezed.

"Then _I'll_ wash it!" You blushed, jumping off the stool. After a moment of consideration, you put the coat on yourself, only so that Sans couldn't wear it and then mock you. "Are we done here yet? You've had loads of customers!" The skeleton looked thoughtful for a second, before nodding.

"Sure, let's clean up."

-

It hadn't taken long to put everything away again. Sans kept most of the condiments inside a fridge tucked away in the corner of the shed, apart from the ketchup - which he'd tried and failed to tuck into his pocket with you noticing. As you walked to Alphys' lab, he squirted some hungrily into his mouth every so often. It was quite a long walk, and you were getting really desperate to go home, so you could finally cover up.

After coming through several security checks, you were awkwardly stood next to a sofa covered in anime DVDs and scattered crisps. After the stool incident, you were prepared to not sit down again for a long time.

"... And that's the last of the reports." Alphys finished, dropping a large stack of unorganised papers into Sans' arms. "After you've ch-checked through them and organised them, you'll need to take them to Asgore.

"Thanks, Alphys." Sans smiled. The two of them were working on something for the king, though what it was you weren't entirely sure. From the looks of their nervous glances at you and hushed tones of voices, it was clearly a secret.

"It's okay. It's a n-nice break from making new clothing attachments for Mettaton." She admitted, gesturing to a large pile of robotic feet with different styles of high-heel on. There was even a pair that looked like converse shoes made into high heels.

"How is Mettaton doing?" You called across the room. Surprised, Alphys turned to you and blinked.

"He's doing good actually!" She twisted her fingers together. "As you know, he's successful up on the surface too. I think he still prefers performing for monsters, though."

"That's nice of him." You smiled.

"Yes. How lovely." Sans curtly said, gritting his teeth together. You hadn't actually thought about Sans' jealousy over Mettaton until now, but why not make him suffer in return for what he'd done to you?

"It's so humble of him. Those shoes look amazing, too! They probably look really great on him." You gushed. Alphys blushed a little at your compliment of her work.

"Y-yes! He designs them himself actually."

"Oh really? God, that's awesome. I wish more men could design their own clothes! He's _so_ confident and headstrong."

"He's.. er... certainly c-confident."

"He's really bold. He knows what he wants, and he's not afraid to ask - I think that's great. What other kind of things are you working on for him?" You were really hamming it up now, but it was all worth it for the look on Sans' face. You'd never seen a face full of such hatred and jealousy. If Mettaton walked into the room, Sans might just dismantle him screw by screw.

"Uh, sure." Alphys smiled, clearly having not looked at Sans. She led you over to a side room, before yanking open the door. Inside was countless metal plates and electronic attachments with dresses, dazzling outfits, and wigs of all shapes, colours and sizes. Clearly, the robot liked having a lot of choice. Immediately, you rushed in and stroked a sequin top.

"These are fabulous! He really thinks of these?" You cried. "God, I wish Mettaton could dress me every day." Behind you, Sans started literally growling, a dark and guttural sound.

"Y-yes he does." Alphys stuttered behind you.

"I bet he looks _amazing_ in them." You wistfully said, stroking a black wig.

"Right. _____, we're leaving." Sans suddenly spat behind you. When you didn't respond straight away, a hand slowly turned you around to face him. It was hard to hold in a gasp as you saw his expression. His sockets were void of pupils, and the swirling blackness within them was brimming with fury and agitation. You'd really hit the nail of the head this time, and Sans had not taken it well. The fingers of the hand holding the stack of papers were slowly curling and uncurling, his teeth grating against each other.

" _Now_." He commanded, pulling you out of the side room. Next to you, Alphys jumped a little before rushing to let you out.

"G-g-goodbye." She barely whispered, not daring to look at Sans. You felt bad for using her in your game - after all, she wasn't the type of person that handled this kind of stress well.

"Thanks Alphys. See you soon!" You called to her as you were yanked out of the door.

As soon as you were alone, Sans stopped and turned to you.

"You are playing a dangerous game. _Don't do that to me again_."

**Notes for the Chapter:**

> Thanks for reading! As ever, please feel free to leave a comment below or send my an ask on my tumblr - underblogger.tumblr.com :)


	8. Revenge and More Revenge

**Notes for the Chapter:**

> This took a while to write, and is a bit of a mish-mash!  
> However, I do hope you enjoy it ;D

The journey back home was tense. Sans didn't let his grip of your wrist loosen at any point, his angry form keeping a fast pace ahead of you as you were lead home like a child in trouble. You didn't dare speak, or even resist him - but the triumphant feeling was hard to shake off. He'd responded to you just as you'd wanted, so easy to wind up. This angry side of him was actually pretty rare to see - mostly he was just funny, lazy, smooth Sans. Seeing the cracks in his chilled persona was not something you saw often.

When you arrived at your door, Sans finally turned to you. Sweat had formed in small beads on his brow, and his breath was heavy - which was odd. He shouldn't be tired as he walks around this city every day - but you couldn't think about it too much, considering his expression. It was unchanging, unrelenting, and still the same look of a monster that had been wound up way too much. Oops.

"Well?" He demanded, staring at you.

"Uh, what?" You dared to question, confused. He sighed in response.

"Are you gonna apologize?" He asked bluntly, as if that had been obvious. Something in the back of your head twitched. _So,_ you fumed, _he called it a game and then acts like it won't come back to bite him in his bony butt? Think again, Sans._

"Are you gonna give me back my underwear?" You innocently inquired, yanking your hand away from him to cross your arms. Suddenly, he smiled. It was unnerving, considering how scary he'd looked around two seconds ago.

"You can have them back any time you like." He grinned, laughing slightly. A feeling of dread crept up your spine.

"Will you give them to me, then?" You slowly asked. Sans shrugged.

"Well, I can't _give_ them to you, as I don't have them." Your brain only processed one emotion; _horror._

"Don't tell me you've - "

"I've hidden them in all sorts of places!" He suddenly snorted with laughter, throwing his head back and almost dropping his papers.

Suddenly, you lunged forwards to shove him, but he deftly moved out of the way.

"Tell me where they are, Sans!" You cried. Terrifying images of your friends finding your underwear filled your brain. Sans only laughed more, tears forming at the corners of his sockets.

"They're... all over... the city!" He gasped, doubling over.

"When did you do this?!" You cried, incredulous.

"I had a whole night." Sans replied, trying to collect himself again. _Hold on,_ you thought, _that doesn't make sense either. How can Sans run around hiding my underwear all over the city all night, but he sweats after one walk that lasted 10 minutes at most?_

"You..." Your sentence didn't last long, because you weren't quite sure what to say. Your underwear was hidden _everywhere_. How were you ever going to find it all?

"Here." He said, stepping towards you. With his free hand, he reached into the right-hand pocket of his jacket - that you were still wearing - and pulled a small piece of fabric out of it. It didn't take you long to realise that it was one of your favourite pairs of panties - black and lacy.

"You had my _PANTS_ in your coat pocket _ALL DAY_?" You shouted. This was _unbelievable_. _Unthinkable._ But also, you privately admitted, it was just like Sans.

"I still can't believe you never looked in the pockets, to be honest." He drawled, back to his casual self. Idly, he began twisting the underwear around his skeletal fingers, his unconscious mind clearly thinking about his hold on them even if he wasn't. Slowly, you reached forward and took them, barely able to move. His eyes searched yours, holding an expression that had flickers of concern.

There were no words to describe the feeling flying through your mind. The image of any of your friends finding your underwear hidden somewhere - in their homes or otherwise - was so embarrassing that you just couldn't speak anymore. Silently, you simply moved past Sans towards your front door. As you pulled it open, you felt a bony hand rest on your shoulder.

"Hey, you look stressed. You should know that I didn't hide any of them where strangers could find them." His voice sounded deep, and genuine. However, it didn't really help as that meant that all of your underwear was hidden in places your friends would find them - people that you would still have to make eye contact with in the future. Realistically, Sans' room was probably the best place to start. As soon as you opened the door, a cheer rang through the house.

"HUMAN! SANS! YOU ARE HOME!" Papyrus whooped from your living room. It was sweet that he was so excited to see you, even though he hadn't strictly seen you yet. In a rush of panic, you realised that you were still holding your underwear - and the last thing you wanted was for Papyrus to run to see you and catch you holding them. As your heard pounding footsteps, you quickly shoved them back into the pocket they came from.

"Hey, bro." Sans smiled, as Papyrus came round the corner. You hadn't heard him enter the house behind you, but you did hear him close the door.

"WE ARE HAVING A MOVIE MARATHON! ALHPYS WILL BE COMING OVER SOON!" Papyrus exclaimed as he threw his hands in the air. The sheer adorableness of his puppy-like expression made your heart melt. However, you knew you were on a mission. As Sans announced his need for ketchup and wandered through to the kitchen, you promised Papyrus you'd just fetch something from your room and quickly ran upstairs.

You knew that watching movies would trap your downstairs all evening, so you had to act fast now. The second you were out of sight, you yanked the black panties up your legs. It took you a second to adjust, the feeling was simultaneously weird, yet relieving. However, you knew you didn't really have time to dawdle and spun around, to see Sans' bedroom door in front of you.

You took a deep breath, before pushing his door open.

It was pitch black, since the sun had already set, and your groped the wall to your left blindly to find his light switch. It took around half a minute before you finally found it. Light flooded the room, illuminating your new surroundings in an artificial, yellow light. You didn't come in here often, and when you did Sans had always been present, so it was really weird to be trespassing like this.

Quickly, you rushed over to his chest of drawers on the opposite side of the room, jumping wildly over the various, discarded pieces of laundry that littered his floor. Old T-shirts, jeans and jogging bottoms seemed to form a new carpet over the real one, that had blue and purple stripes. His first drawer was full of random stuff - paper, small bits and pieces and some science equipment.  Clearly, it was his junk drawer. His second drawer was actually full of his own underwear.

"Fuck." You whispered to yourself, the temptation to take a pair bubbling furiously in your gut. _Should you, though?_ You stared at his messy piles of boxer briefs, as if looking at them more would magically give you the answer. Downstairs, you could hear your friends chatting, idly. You had to hurry. Not wanting to stoop to his level, you left his underwear where they were and pulled open his last drawer. A long sigh escaped your lips - nothing here either, just pairs of unfolded trousers.

Desperation washed over you as you heard the voices downstairs grow louder. _They were leaving the living room!_ Frantically scouring the room, you realised one of your bras was hung on the back of his door, where his coat was usually hung. You didn't have time to think about its placement - the footsteps were coming upstairs now. In one panicked motion, you yanked your bra off his hook, slammed the light switch to leave the room as it was, and leapt out of Sans' room, panting. Hastily, you hid your bra behind you, only to find that it was Sans that had come up.

"You look... weird." He slowly said, examining you carefully. His eyes travelled all the way own to your feet, before running slowly back up again.

"Wow, you don't even try to hide it when you do that, do you?" You blurted out, not catching the words before they left your mouth. Sans only grinned in response.

"You're worth looking at." He winked. A blush crept up your cheeks. A second's pause went by before he took a step toward you, stroking a hand along the fur lining of his jacket's hood, draped around your shoulders. "You're still wearing my jacket."

"Do you want it back?" You slowly asked, hoping he'd say no. In truth, you were quite enjoying wearing it, even considering why you'd started wearing it in the first place. Having the smell of Sans around you all day was heavenly.

"Didn't you want to wash it?" He smirked.

"It's lovely and warm!" You smiled, snuggling into it, trying to think of an excuse to keep his smell around you.

"So is _somewhere else_ , I'll bet." He grinned, evilly. His suggestive expression made you melt a little, but you were determined to act indignant.

"Hey!" You cried as you lightly cuffed his shoulder. He smiled down at you, as he slowly took his jacket off your shoulders. "Wait, no...!" You protested, but he didn't seem to notice you. When he saw your hands, still holding a bra, he grinned madly but still didn't say anything. As you stood there, still confused, Sans disappeared into his room for a few seconds before coming back out with a dark gray, woolly jumper.

"If you're cold, I'm surprised you didn't just take one whilst you were snooping in there." He taunted, placing the jumper in your hands and nodding to the bra curled up in your hand. Without another word, he then turned around and disappeared downstairs.

Dumbfounded, you stood there for a few seconds processing what had just happened. Clearly, Sans knew that you must've gotten the bra from his room - but for some reason didn't seem too mad about it. _Then_ , you thought, _there was the matter of his jumper_. The fabric curled in your hand was soft, as if the item of clothing itself was just asking you to put it on. This day was taking weird twists and turns.

-

Once you'd put on the bra under your shirt and the jumper over it, you headed downstairs. In the lounge, Alphys had arrived and was curled up with Undyne on the love seat, leaving Papyrus and Sans at on the other, larger, sofa. With an excited gasp, Papyrus frantically patted the seat next to him.

"Hey!" You whispered as you sat in-between the two brothers.

"We are going to watch a film called Lord of the Rings!" Papyrus excitedly whispered back. It was so cute that you didn't bother to tell him that that was the series name, not the films. Next to you, Sans chuckled softly.

"Hey kid. Come to sit next to your good pal Sans?" His voice was surprisingly close to your ear. Trying to act cool, you only glanced at him and shrugged, grinning cheekily.

Around halfway through the film, it became clear that Papyrus was asleep. Across the other side of the room, Alphys and Undyne also looked pretty tired - like they'd be joining Pap any second. On the screen, the film raged on. It was pretty impressive that anyone could've fallen asleep, considering how loud if was playing - and how many screaming battle scenes were going on too. Behind you, Sans was clearly still awake, as every so often he'd snort with laughter or gasp slightly at what was going on.

"Are they asleep?" You gently whispered to Sans, looking over to Alphys and Undyne. He straightened up before glancing their way.

"Looks like it. Why, d'you want me alone?" He winked. You couldn't help but laugh.

"Do you _ever_ stop?"

"Stop what, kiddo?"

"You know what."

"Y'know, I'm not sure I do. Care to explain?"

"The constant flirting?" At your words, Sans grinned wildly, an expression of satisfaction spreading across his face. He'd gotten you to admit it.

"Do you want it to stop?" He asked, eyeing you with a shit-eating grin on his face. He was unbearably attractive, his skeletal features gently illuminated by the flickering TV.

"I'm sure you know the answer." You teasingly replied, not wanting to give him any more satisfaction. He only grinned more.

"Good. I'm not done yet."

"Oh, really?"

"Yeah. Got plenty things in store. Including..." Sans trailed off as he reached behind him. Your breath hitched in your throat. Slowly, keeping solid eye contact, he pulled his hand back out from under the cushion that he'd been leaning on for the past hour and a half. He dropped something in your lap.

When you looked down, you realised it was a pair of your panties.

"What the fuck?!" You exclaimed wildly. You were more surprised than embarrassed.

"Shush, shut up, the others are sleeping." Sans hurriedly rambling, clapping a bony hand against your mouth. When you looked at him angrily, laughter gently rumbled from him. "You're cute like this."

"How long were my pants under that?!" You harshly whispered once you'd ripped his hand away from your mouth. Sans shrugged.

"Since last night. I told you, I've hidden them everywhere." His words left a long silence in the air, only punctuated by mood-ruining grunts of orcs. Slowly, he picked up your pants before pressing them into your hands. He looked into your eyes for a long time, amusement spilling out across his features, before he slowly stood up.

"This is going to happen a lot, so you should get used to it, cutie."

As he walked away, fury filled your mind. You weren't about to just let this slide - or about to lay down let him make a fool out of you again. In a wild rush of adrenaline-fuelled energy, you ran up to your room to your computer. It didn't take long to find some rather questionable porn on the internet - because, hey, it _was_ the internet - and in a mad rush you sent a lot of pictures to the printer.

Waiting in your conservatory for the images to print was a very tense 2 minutes. You were constantly aware that right in the next room, 3 of your closest friends were asleep and could realistically wake up and come in at any second. Finally, after they were all done, you were pretty proud of yourself. Since you'd printed them on photo paper, they actually looked pretty legit and magazine-esc, which was perfect for your plan.

With your heart pounding hard in your chest, you ran to the front door. There, on the side, was the report that Sans was going to take to Asgore tomorrow. Quickly, you grabbed the pictures you'd printed out and shoved them in random places in the report. Luckily, it was big enough so that they fit right in the pile - it was extremely hard to tell that you'd even touched them.

 _Well Sans_ , you thought. _Let's see how much you enjoy work tomorrow._

**Notes for the Chapter:**

> Thanks for reading! As always, please feel free to leave a comment below, on my tumblr at underblogger.tumblr.com , OR tag a post on tumblr with #UBTIAS :)


	9. A New Wall Display

**Notes for the Chapter:**

> Sorry, this is late!! The next chapter is also going to be late because of mock exams I have to do this week, and then a party taking up my weekend! Sorry!!

Your day at work had been one long wait to get home again. Part of you was incredibly nervous about what you'd done, but another part of you couldn't help laughing a little whenever you remembered it. Working in retail was tiring, and by the time you got home you really wanted to curl up and watch something that didn't require much thought.

A small sigh left your lips as you unlocked your front door. As you stepped in, you noted the silence and decided that no one was in.

"Hello?" You called, and shrugged when no answer came back to you. That's what you'd been expecting anyway. After dumping your bag in the kitchen, you slowly headed upstairs, your mind drifting to planning a nice, relaxed evening. However, when you got into your room you froze instantly.

There, stuck on your wall, was every single picture you'd shoved into Sans' report the previous night. Underneath was a small note in familiar handwriting. Moving closer, you realised the handwriting was Sans'. Of course it was.

**Nice try.**

Your heart went up to your mouth. _How had he managed to do this? He wasn't even home yet!_ You knew that Sans usually finished work after you did, but here were these pictures. All stuck onto your wall in an almost artistic fashion.

When you realised that you'd been staring at this display for a long time with your curtains wide open, you quickly rushed to take them down, embarrassed. If anything, it was more worrying that you hadn't managed to trick him, because it meant Sans still had the upper hand - and now he had even more reason to concoct devious revenge. You had to be ready. You had to be -

"You." A low voice appeared behind you. Jumping out of your skin, you spun round, the offending pictures still in your grasp. You opened your mouth, but no words left them.

In front of you, Sans' usual grin had twisted into something darker - an expression of knowing and of power. His pitch black sockets held an expression of dominance. His usual blue jacket was gone, leaving him in only a red T-shirt and black jeans. You could almost feel the magic roll off him in waves, making your hair stand on end.

"Oh, got nothin' to say? I have a few things." Sans drawled, almost casually if not for the angry undertones. Slowly, he began walked towards you and you backed away without thinking. He smirked, not stopping, until your back was against the wall and he stood intimidatingly over you. "Do you know what that report was for? Do you know if it was important, or what was in it?"

You gulped, not replying. You knew any words that left your mouth would be weak, feeble, not able to match the strength that was in his.

"Answer me, please." He growled. He'd never looked like this before, angry, but with so much control.

"I... I don't know." You stammered. You voice was half the volume you'd wanted it to be.

"No. You don't." Sans said, after a pause. "I also can't tell you what was in it. That's how important it was." Another silence hung in the air.

"I'm sorry." You weakly said, wishing that it would be enough. Of course, it wouldn't be, and you knew that, but maybe it would appeal to Sans' good nature.

"Luckily, you don't need to be sorry. I caught your little trick in the waiting room, just minutes before I went in." He used a skeletal finger to lift your chin up, your eyes locking onto his empty sockets. "I'll admit, it nearly got me. Poor ole' Sans would've been real embarrassed then, wouldn't he?" His smug, patronising drawl ran right through you. It was almost shameful, that this was turning you on. As if he'd read your mind, Sans placed one hand against the wall, trapping you, and used the other to hold your hip. Slowly, he got closer and closer until you could feel his breath on your neck. A small part of you questioned how he even had breath, but the feeling was so electrifying that it soon escaped your mind.

"You tried so hard. But, in the end, you failed. I saw through your little plan." Sans whispered, almost as if he was talking to himself. With every word his voice got deeper and deeper. Your knees were weak.

"I got pretty close." You tried to point out, sounding vaguely indignant. Sans only chuckled, darkly.

"I'll get you pretty close." He drawled. Usually, a joke like that would make you groan in exasperation, but this time it had a whole other effect. As your breath hitched in your throat and your heart skipped a beat, Sans leaned slowly down.

"I love it when you go crazy for me." He said, before you felt his teeth nibble on the side of your neck. _Bite it. Bite me,_ your brain urged. However, Sans remained tantalisingly restrained, his mouth barely making contact. Slowly, you placed a hand around the back of his skull to try and pushed him further towards you. Sans didn't respond to your desperate attempts, but instead you felt a pair of lips appear on your neck, gently sucking. If he carried on like this, it would probably form a hickey, but that was the last thing on your mind right now. You needed him. You needed him like this. If only he would -

"Heh. Look at you, kiddo. Blushing, gasping, grasping me... it's almost like you're begging for it."

You tried to keep your dignity.

"I... I don't beg." You insisted as he took his head away. All of your body felt weak, wanting, but you needed to gain some sort of footing here. Sans clearly had all the power.

"Mm-hm. Of course you don't." He smirked, before moving his hand up and resting a thumb on your mouth. Barely daring to move, your breathing grew heavier  as he ran the bone along your soft lips, his expression intense and thoughtful. After a long minute, he pulled away and stepped back.

"In any case," He began, "it looks like you didn't want my help in finding your underwear, judging by your actions. Good luck scouring the city for your panties." The words swirled inside your stomach. That was completely unexpected.

"Wait!" You cried desperately as he turned away. Without his help, it could take your months to recover everything he'd taken. On your own, it was pretty hard to guess where he could possibly have hidden them all.

He didn't turn back, and left your room without a word. Grumbling and exhausted from the roller-coaster you'd just been on, you clambered into bed and swiftly pulled your laptop onto your lap. All you needed was a distraction - a way to stop thinking about what had just happened for a while.

-

After half an hour of trying and failing to concentrate on Netflix, you decided that getting into your pyjamas and making yourself a hot chocolate could help you calm down. It was hard to stop your mind constantly running around, repeating every word Sans had said, every touch he had placed on you.

You found yourself in front of your mirror, idly watching yourself as you got changed. Slowly, you shrugged off your jumper, and then your T-shirt, and stood for a second to bask in the rush of cool air. Living with two other people meant that you didn't get much time to just feel free and be naked, so you wanted to take every moment of privacy that you could get.

After you peeled your jeans off, you looked at your body in the mirror. You were still wearing a bra and pants, but it was nice to just relax for a moment, without being constantly encased in fabric. Your reflection grinned back at you as you absent-mindedly fixed your hair. _Okay_ , you thought to yourself after a minute or so, _it's probably time to get some clothes back on_.

"SANS!" A voice cried as you bent down to pick up your pyjamas. You smiled to yourself, making a mental note to say hi to Papyrus when you went downstairs.

"SANS, WHAT ARE YOU LOOKING AT? WHAT IS IN _____'S ROOM?" Hearing this, you froze. What was Papryus saying? Was Sans - ?

"No, bro, don't come here! Don't look!" A panicked voice replied. As you turned to look over your shoulder at your door, you realised that it had been ajar this whole time, and Sans had been awkwardly looking through it. His face was flushed a deep blue as he made eye contact with you.

You'd never gotten into clothes so quickly in your life. Jumping into the shorts and T-shirt in your hands, you stormed over to the door and threw it open, exposing Sans fully. He jumped away from leaning against the wall.

"Sans, were you fucking _watching me change_?" You fumed. Sans looked like he wanted to disappear into the floor, an expression of someone who had created unsalvageable disaster.

"No! Well, yes... but the door was open! I was gonna tell 'ya, but... I don't know! I'm sorry!" He rambled, holding two skeletal hands in the air and sheepishly trying to grin. "I am really sorry!"

"What the hell, Sans? Total invasion of privacy!"

"I know, I know! I didn't mean to, sorry!"

"You _didn't mean to_?!"

"You just looked so..." As Sans trailed off, the lust in his eyes became clear. The reality that Sans had seen you in underwear - and it had unravelled him - was dawning on you more and more by the second. Crazy images of him ripping the clothes back off you crossed your mind. You stepped towards Sans, before remembering Papyrus and freezing.

It was like you both had realised that he was there at the same time. It was an unspoken pact that many of your friends had, that Papyrus was far too innocent to be shown any of this kind of thing. Certainly, the look in his brother's eyes - of lust and deprivation - was something he shouldn't be seeing.

"Hey, Pap, wanna make some hot chocolate with me?" You smiled down at him, to where he stood halfway down the stairs. At your offer, he clapped his hands in delight and ran off quickly to the kitchen.

Before you walked away, you turned to Sans.

"If you ever do that again, I'll do a lot worse than put dirty pictures in your reports, you _filthy_ skeleton."

**Notes for the Chapter:**

> Thanks for reading! As always, please feel free to leave a comment below, on my tumblr at underblogger.tumblr.com , or tag a post on tumblr with #UBTIAS :)


	10. The Most Exciting Hot Chocolate Ever

**Notes for the Chapter:**

> The basis for this chapter was inspired largely from a idea in the comments from Varikai. Their idea made me laugh so much that I had to include it, and it was really fun to write, too.  
> Sorry I was gone so long! However, my mocks are over now, so hopefully I should be able to go back to the usual upload schedule. :)

By the time you got down to the kitchen, Papyrus was already stood in the middle of the room. As he eyed you carefully, you noticed how he was nervously shifting from foot to foot.

"HUMAN. WHAT _WAS_ SANS LOOKING AT?" Papyrus question, his innocent, inquisitive eyes searching your own. It was hard to think of something to tell him - you didn't really want to lie to him.

"He was just looking at me, trying to scare me!" You tried. Your skeletal friend seemed satisfied with this answer, but the guilt of being dishonest to him curled your stomach into a knot.

Papyrus hummed happily to himself as you got out everything needed for hot chocolate. The tune sounded a little like one of Mettaton's singles, which brought a smile to your face as the image of a jealous Sans popped into your head. Amusement threatened to make you snort with laughter, but the worry of being asked more questions that you didn't want to answer held it back.

"Okay," You said, halfway through the process of making the drinks, "Papyrus, do you want to stir them? Make sure there's no more lumps of the powder in either mug - and do it gently!" Following your advice, the skeleton leant down over the two cups, his face screwing up tightly as he started concentrating really hard on not spilling any milk onto the counter.

At this moment, you heard the door creak and turned to see Sans slowly stroll into the kitchen. Anger flared up in you again as he made eye contact with you, before sheepishly looking away again, a bright blue blush glowing on his cheekbones.

As you watched him try to pretend you weren't there, a small idea formed in your mind. Since Papyrus was busy, you could realistically do a lot of things out of his field of vision.

You took one step towards Sans, and his eyes shot back to watch you. A slow, evil grin spread across your face that you just couldn't help. He looked alarmed, then confused, then looked away and pretended not to look at you.

Slowly, your grasped the hem of your shirt and wriggled the fabric slightly. Sans' eyes were transfixed on your hands. You stole a quick glance at Papyrus, before realising he was still totally oblivious to the fact that Sans had even entered the room, never mind what you were about to do.

As quick as you could, you tugged the bottom of your shirt upwards and raised it to your chin, revealing your barely-covered breasts. After giving Sans a millisecond to realise what he was looking at, you pulled your top back down as fast as you'd pulled it up.

Shock was the only feature on his pale features as his mouth hung wide open.

It was really, _really_ hard to hold back laughter. However, the urge to laugh subsided into intrigue as something in Sans seemed to change. In the black pit of his open mouth, something blue was forming. Was that... _a tongue? No way,_ you thought. _Sans only forms a tongue like that when he's aroused._

Slowly, the look of shock on Sans' face disappeared as he practically ran over to sit in a chair. Hurriedly, he then sat firmly down into a chair, before pulling the morning's newspaper into his lap.

 _Wait_ , you thought. Something was dawning on you. _Sans only forms a tongue like that... when he's AROUSED._

You clapped your hands in glee without thinking. Sans had an erection! You could've cackled with laughter, the joy of victory filling your mind. _You'd given Sans a boner_.

"HUMAN!" Papyrus suddenly called behind you. "I HAVE FINISHED STIRRING THE - OH. SANS!" Turning swiftly around, you realised that whilst you'd been celebrating to yourself, Papyrus had turned fully around to see his brother at the kitchen table, his eyes transfixed on the newspaper that he'd already read.

"SANS, I'M SORRY, WE DIDN'T MAKE YOU A HOT CHOCOLATE! WOULD YOU LIKE SOME OF MINE?" Papyrus offered, holding his mug in the air. The burning hot liquid sloshed around alarmingly.

"Yeah, Sans!" You joined in, smugly. "Come over here and have some of ours!" Sans shot you a desperate look.

"It's... it's ok. I'm ok here." He mumbled, rustling the newspaper for effect.

"COME HERE LAZY BONES!" Papyrus scolded, pointing to a spot just in front of him. "YOU CAN'T SIT IN CHAIRS FOREVER!" In his seat, Sans squirmed uncomfortably. You watched as he shifted from side to side nervously, his eyes flitting from the newspaper, to his crotch, and then to you.

"I'm tired. Might sleep down here." He said, faking a yawn. Next to you, his brother sighed, irritated.

"YOU WILL MAKE ANY EXCUSE. YOU'RE GETTING WORSE!" He rambled, throwing his hands wildly around. You had to dodge the boiling liquid that flew out of his mug several times as the skeleton continued to  exasperatedly stare his brother down. Clearly, Papyrus was determined to win the argument.

"Why don't you bring it over here?" Sans suggested, his eyes expressing a false confidence that was shown up by his shaking fingers. He took a long, pleading look at you, begging to be saved from this situation.

"IF YOU DON'T COME HERE YOU WON'T HAVE ANY!" Papyrus fumed. It was surprising to hear Papyrus get mad like this. Unfortunately, that meant that it was probably time to step in and stop the argument.

"Hey, Pap." You calmly said, gently resting a hand on the tall skeleton's shoulder. "It's not Sans' fault, he's had a really long day at work. I'll give him some of mine and then he'll come upstairs to read you a story, ok? It's late." At your words, Papyrus visibly calmed down.

"Okay." He sighed, a touch of tiredness flashing over his eyes before he straightened up fully again. "I, THE GREAT PAPYRUS, AM GOING TO BED!" He cried, before rushing upstairs.

A long silence filled the room.

"I can't believe you got an erection." You finally said, barely daring to look at Sans.

"I can't believe you flashed me when Papyrus was right there." He replied, his voice sounding just as incredulous as yours did. Slowly, you walked over to him and set your mug down on the table.

"I don't think I took it too far." You said, looking down at Sans. He still hadn't removed the newspaper, and a faint blue glow shone through the thin pages.

"I think that maybe this whole thing went too far. You nearly made me show hardcore porn to the _king_."

"You've hidden my panties _all over the city_!"

"You deserved that."

"Did I? Did I really do anything to deserve _that_? Maybe _you_ took it too far."

"Maybe." He mused, quietly. A long pause occurred where you both simply looked into each other's eyes, each waiting for the other to act. When you finally did, it was as if you both thought the same thing at once.

In a flash, Sans pushed his chair away from the table, right as you ripped the newspaper from his phalanges. There was a slight tearing sound as it left his grasp, and a loud wrinkling noise as you threw it onto the table. You found yourself clambering onto Sans, messily straddling his lap. As you rested your hands on his shoulders, facing him, you realised that Sans' arousal still hadn't gone away - even after all this time.

You could feel something hard, and _big_ , pressing into your crotch. No sooner had you realised this than you experimentally ground yourself onto it, coaxing a deep, desperate moan from Sans. The feeling of his member rubbing against your most intimate place - at last - ignited sparks within you. it felt like the excitement you felt was seeping into your very soul. You were watching your own hips, transfixed, as you slowly rubbed against it again. You gasped loudly, without thinking, and Sans clasped a hand against your mouth.

"I know I moaned before, but you gotta remember that Pap is still - "

"SANS!" A voice called from upstairs. "WHEN ARE YOU COMING UP FOR MY STORY?" Underneath you, Sans sighed.

"How the _fuck_ am I meant to get rid of this now? It was hard enough before!" He hissed. The double meaning made you chuckle a little, but the sound of feet coming down the stairs stopped you both in your tracks.

Leaping from his lap, you brutally shoved the newspaper back towards Sans, before roughly picking up your mug of lukewarm cocoa. You took a long gulp of it, trying to make it look like you'd done as you'd said and had given Sans some, whilst Sans desperately straightened his jeans out.

"Hey bro." Sans smiled as Papyrus walked in.

"HURRY, SANS! I HAVE BEEN WAITING FOR A WHILE!" He whined, tugging Sans' shirt like a small child. Sans only chuckled casually in response, before standing up. A strained expression furrowed his brow bone as the blue glow faded. You weren't about to question how he was concealing his arousal, but it was pretty funny to watch.

As the two brothers left the room, you saw Sans quickly glance back at you, before closing the door behind them.

**Notes for the Chapter:**

> Thanks for reading! As usual, feel free to leave a comment below to tell me what you thought, send me an ask on my tumblr at underblogger.tumblr.com , or tag a tumblr post with #UBTIAS :)


	11. Problematic Party Games

**Notes for the Chapter:**

> *Insert evil laugh here*
> 
> I'm not saying that I'm the devil incarnate, but... read it and you'll see.
> 
> I had a LOT of fun concocting this in my evil lair of story torture.

The week passed by quickly. You were working every day, so they all seemed the same. You went to work, came home, ate dinner with Papyrus, barely saw Sans, and then went to bed. By Friday, you were feeling pretty ready to cut loose.

"Undyne?" You asked, as the call connected. On the other line, you could hear odd rustling. "Are you there?"

"Uh. Hey. Oh, _____, it's you!" She said, her voice sounding a mixture of tired and rushed.

"Are you busy with something? Want me to call back later?"

"No, it's ok. I can talk. What's up, bestie?"

"Hey, it's been a really long week, and it's Friday today, so I was thinking - wanna come over tonight? We can get some drinks, have a laugh?"

"Uh..." There was a pause on the other end of the line. You could hear hushed voices. "Yeah, I'm free. Is it okay if I bring Alph and Mett too, though?" You took a little while to consider this. Whilst you loved Alphys' company, you weren't sure how happy Sans would be with Mettaton in the house. _However_ , your brain interrupted, _Sans also doesn't run your life_.

"Yeah, bring 'em!" You happily said. Undyne told you she would be over at 7, before ending the call.

As you put the phone down, you could hear Papyrus clattering pots and pans downstairs. It was probably a good idea to tell both of your roommates as soon as possible - after all, _surprising_ Sans with Mettaton would be even worse.

"Hey, Pap!" You called, as you walked down the stairs.

"HUMAN!" He cried in delight as you entered the kitchen. He was wearing a white apron over his battle body, and had a large ladle in his hand. Clearly, he had been just about to cook something when you'd walked in on him.

"I've invited Undyne, Alphys and Mettaton over later for a few drinks. Do you wanna join us?" You asked, as a huge beam spread across Papyrus' face.

"I WOULD LOVE TO! SHALL I COOK EXTRA SPAGHETTI?" He eagerly offered, bouncing from foot to foot. It was truly adorable to see him so happy.

"Yes, that would be awesome, we've gotta have something to eat! They'll be over at 7, okay?" Papyrus only cackled with glee as you left. Next up, Sans.

As you slowly made your way to Sans' room you took some big, gulping breaths to try and calm yourself down. It was a little nerve racking, since Mettaton was coming, but ultimately you knew you were being ridiculous. _It was your party!_

You knocked. There was a long pause, and then no answer.

You knocked again. This time, you heard a quiet, incoherent mumble from inside. Not knowing what to do, you took that as a signal to go ahead and slowly pushed his door open.

Sans' bedroom was dark, as the curtains were pulled firmly shut - even though it was still light outside. There, on his bed, Sans himself was curled up in a big pile of sheets. You couldn't really tell whether he was awake or not, since his body was angled away from you.

"Sans?" You almost whispered, trying to keep your voice low.

"What? Uh... hey." He mumbled, turning to face you.

"Have... have you been asleep all day?" You asked, incredulous. Sans only chuckled under his breath.

"Not _all_ day." He said, a small smile spreading across his face.

"Look, I'm having a gathering. Undyne, Alphys and Mettaton are coming over, and we're gonna have a few drinks." A silence hung in the air as Sans processed this information. "It would... it would be great if you came, too." You admitted. At this Sans grinned even more.

"Well, if you want me there so bad, I guess I'll let you pull me away from my busy schedule." He drawled, pulling himself upright. "After all, I can't leave you alone with that robot for two seconds either, can I?"

-

It didn't take too long for you to get ready. After all, you wanted to change out of your work clothes but it wasn't like you needed to look like you'd made a huge effort - these people were your friends, after all. In the end, you'd simply put on a black pair of jeans and strappy red top that hinted at your cleavage.

The doorbell rang as you were looking in the fridge for some drinks.

"Hello!" You loudly called as you ran to your front door. Your three friends laughed at you as you struggled to open the door with cans of cider in your hands. When you finally managed it, they took their shoes and coats off without your prompt, meaning you could run through to the living room to put your drinks down and start playing a random playlist on your phone.

"Hey, I was thinking when we came over..." Undyne began as she walked into the room behind you. "Alphys and I have looked up some human drinking games on the way over, and I'd love to try some out!"

"Yeah, sounds great!" You smiled. Alphys and Mettaton had also come in by this point, and both were carefully settling themselves down onto your larger sofa.

"Is it okay if I do Mett's wiring here? It won't take a few minutes." Alphys nervously inquired.

"Of course! I'll go see where the brothers are." You smiled. However, as you said this, Papyrus came balling in all by himself.

"FRIENDS!" He excitedly cried, rushing towards Undyne with open arms. She caught him in an affection hug, the two of them laughing as if they hadn't seen in each other in weeks.

"Okay, okay!" You called across the room, trying to calm the calamity that had already started to begin. The room fell quiet, apart from the occasional sparking noise coming from Alphys. "Undyne, you wanted to play some games?"

"Yes!" She cried, clapping her hands together. "Everyone, sit in a circle!" As Alphys clamped Mettaton's chest plate shut and booted him up, the group gathered in a circle on the floor.

"What game's first?" A low voice drawled behind you. After you jumped out of your skin, you turned to see Sans stood in the doorway.

"Sit down and I'll tell you, punk!" Undyne half-yelled, pointing deliberately to a spot between you and her.

"Sure." He drawled idly, giving you a quick glance as he sit by your side.

"Okay," Undyne began. "The first game is called 'spin the bottle'." Internally, you groaned as she pulled out an empty wine bottle. This game had never gone well for you in the past.

"Everyone down their first drink!" She called. "We kind of need to be intoxicated to start this." As the group drank, an awkward silence was filled by Mettaton's gentle, tuneful humming to the current song playing. Clearly, Alphys had programmed him somewhat strongly, because out of the corner of your eye you could see him happily swaying from side to side. Once everyone had finished binge drinking their first drinks, light giggles filled the room. It hadn't really taken long for the alcohol to started taking it's affect.

"Okay, here are the rules. I spin the bottle, and whichever two people it lands on have to kiss." She giggled. "And - there are no changing the bottle's position. It lands on who it lands on."

As she spun it the first time, the room held its breath. the strength with which she'd spun it made it take a while to slow down, before it eventually landed back on her.

"Me!" Undyne cried, holding a scaled hand in the air. "And..." She spun it more gently the second time, and it didn't take the bottle long to slow down. It landed on Alphys.

"Ah! Easy!" She triumphantly laughed, before quickly pulling her girlfriend over for a peck on the lips. "Next up..." She began, spinning it again.

You heart skipped a beat as it landed on Sans. A small grin tugged at the corners of Undyne's mouth as she stole a glance at you before spinning it again.

 _Of course_ , you thought. _She's only playing this because she wants to play matchmaker_. You took a hefty swig of your drink as the bottle spun agonisingly slowly. It turned towards you. It started to stop. It kept moving, kept turning, and landed back on Sans.

"Oh!" Undyne exclaimed, clearly disappointed. "Well, you can't kiss yourself. Let's spin again."

The next spin landed on you. Every muscle in your body was tensed. Papyrus announced that the spaghetti was probably ready and left the room. As the bottle was spinning again, you started making a list of who would be best and worst to kiss right now. Of course, in social terms, the worst person for it to land on right now would be -

"METTATON!" Undyne yelled, clapping her hands together. Dread filled your whole body. You couldn't get out of this.

Across the circle from you, Mettaton took a deep breath in and smiled at you. It was a smile of triumph and excitement, the false alcohol and seduction seeping through into his facial features. You bit your lip in nervousness before shuffled forwards.

Slowly, Mettaton took a hold of one of your shoulders, pulling you towards him, as his lips met yours. They were surprisingly soft and warm, considering the fact that he was made of metal, and all you could hear was the blood pumping in your ears and the mediocre song playing in the background. Mettaton didn't release you from his grip as his silicone tongue slowly entered your mouth. You knew you should break away, but you weren't sure you could with his grip on you. Plus, you were ashamed to admit that this felt pretty good. Clearly, he had done this before. He rested his hand on the back of your head, but right as he did this you felt a bony hand grab your arm and pull you backwards. You landed on your ass in shock. It took you a few seconds to process the situation in front of you.

Next to you, Sans was growling audibly, his left eye flaming blue. He didn't release his grip on you, but his gaze was fixed straight towards the TV star, who was lazily returning to his place in the circle. A drunken, blissful smile was plastered all over his carefully crafted features. Apparently, he wasn't ashamed of himself.

"Okay!" Undyne said, kneeling up. "Let's uh... let's play a different game!" She added, desperately trying to cut through the tense air.

"Make it a better game than this one." Sans spat through gritted teeth, unmoving. There was a long pause. The robot and the skeleton never took their eyes off of each other, Sans' hand only tightening on your right arm as the animalistic growling still rumbled in his throat. You should've been scared, but it was actually a little arousing.

"Let's play... seven minutes in heaven!" Undyne cheerfully said, standing up. She took a long drink out of her beer can before turning back towards you.

"Sans and ____, you can go first."

**Notes for the Chapter:**

> Thanks for reading! As always, feel free to leave a comment below, send me an ask on tumblr at underblogger.tumblr.com , or tag a tumblr post with #UBTIAS


	12. Seven Minutes In Heaven

**Notes for the Chapter:**

> WARNING: SMUT
> 
> *mad cackle*
> 
>  
> 
> Also, a little note, I changed the word 'tea' to 'dinner' in the previous chapter because many of you thought I meant tea the liquid, when I meant tea the meal :')

"Here, in here!" Undyne excitedly squealed, as she stood in front of a tall cupboard you used to keep people's coats in. Quickly swiping all of the jackets out of there, she held the door open wide and looked back at the two of you. "I'm sure you both know the rules. If not, _____ can explain it for you, Sans!"

You didn't look at each other, but you couldn't help feeling excited.

As she pushed you both into the small space, you could hear Alphys cackle manically from down the hall. Clearly, they had both planned this. You didn't manage to get a word in edgeways as Undyne rambled about what a small space it was, and how she was sure neither of you were going to be claustrophobic. After she closed the door, you heard the scraping of a key, before the click of a lock.

"So... we're stuck here." Sans said, after a short pause.

"Yes... yes we are." You replied slowly. You looked up at him, and couldn't help the wave of attraction that rushed through you. His left eye was still aflame, but it was his expression that caught you - he held a look of intensity and need that you hadn't seen before. That was all it took. You opened your mouth to speak, to fill the silence, but you both knew what was happening.

Suddenly, Sans wrapped a hand around the back of your head and pulled you into a kiss. Soft tingles of magic ran through you from his lips, and then tongue. He kissed you hungrily, needily, and desperately. This had been coming for a long time - and you didn't realise just how much you had been needing it. He put his other hand on your waist and you wrapped your arms around his neck. As you continued to roughly kiss, he turned you away from the door and roughly pushed you against the wall, expelling the air from you in a high-pitched gasp.

"Fuck." He swore as he pulled away. You locked eyes with him as he regarded you, the sound of lusty pants filling the dark, small space. He seemed to gain control of himself as a smirk spread across his face and he leaned in again. You closed your eyes, expecting another kiss, but it came as a surprise when you felt sharp teeth biting your lower lip instead. He nibbled at it for a few seconds, before moving down to kiss your neck. Animalistic want pulsed through you and you desperately tried to rip his shirt off. The two of you parted for a second, in which Sans pulled his t-shirt roughly over his head before slowly peeling yours off. As you started kissing again, he reached around you and started fiddling with your bra. You had to hold back a laugh as he fumbled and tugged at the clasp uselessly.

"I... uh... fuck." He growled, dropping his hands and staring at you. You bit back a grin as you reached around to undo it yourself.

"Don't worry, all males struggle undoing a bra. Human _or_ monster." You smiled, starting to peel your bra off.

"Oh, so you've been with other monsters before?" He asked, a look of possession haunting his skeletal features.

"Um, actually no." You admitted.

"Good. You're _mine._ " He growled, before taking your bra off and throwing it to the ground. You saw a look of a small boy walking into a candy shop cross over your face as he saw your naked chest, but it as quickly covered by the familiar look of dominance. His words made you weak at the knees. As your face crashed into his once more, you started moaning slightly, grasping at his ribcage. A deep guttural growl rumbled through Sans as he took one of your breasts in his skeletal hand, squeezing it slightly.

"Oh my god." You moaned, "That feels so good." Sans only smirked a little before gently pinching one of your already hard nipples, enticing another gasp from you. It seemed to egg him on, and as you gently held a hand on the back of his skull, he leaned down and took one in his mouth.

You called his name out, a little louder than you'd intended. It was easy to forget that your friends were still in the house when one skeleton could make you feel this good. Sans' hands roamed wantonly all over you, reaching down to the waistband of your jeans and then running up your waist, before groping your breasts and running his fingers through your hair. You eagerly grasped a hand to his chest, wrapping your hand around one of his ribs and rubbing the inside gently. You could feel him stiffen as you did so, and he bit down on your breast a little, before starting to suck on its side.

"Fuck, Sans, I'm going to be covered in hickeys." You sighed. He chuckled a little.

"Good. Now that fucking robot will know who you belong to." He paused as he straightened up to look you in the eye. The same expression of intensity and possessiveness from earlier had returned, and he gently held your face in his bony hand. "You are fucking gorgeous. Everything about you. Your body, your face, your hair... and you're such a _goddamn tease_. Do you know how long I've wanted this?" The desperation in his voice sent a small power surge through you.

"Well aren't you lucky that you're getting it?" You smirked. He only moaned deeply in response and pulled you into a kiss. Fireworks shot through you - every touch was electric and every kiss was magic. You could never get enough of kissing him, touching him, feeling him touch you. It became more and more clear how aroused Sans was as you felt something hard pressing against your hip. You smiled as you continued to kiss him, slowly reaching your hand down to brush over it. He twitched like crazy when you first touched it, before a small laugh escaped his non-existent lips.

"More." He moaned, kissing you again. As he pulled you against him, you gently wrapped your hand around the hard shape. It was hard not to gasp at its size - you'd felt it the other day but you hadn't realised it would be so big. As you began you gently run your hands over it, he hastily unbuttoned his jeans. It didn't take him long to pull them - and then his boxer-briefs - down to his ankles, allowing his member to spring free.

You took a second to look down at it. It was bright blue, and glowed dimly in the darkness of the cupboard. You were so close together that it poked you in the stomach. Gently reaching down to take it in your hand, you looked up to smirk at Sans.

"Clearly, you're excited about this." You grinned, biting your lip.

"Fuck, you're sexy even when you're mocking me." He groaned, planting a kiss on your cheek.

Gently, you wrapped your hand around Sans' arousal. He moaned loudly as you began to rub your hand back and forth, the friction enticing deep growls and groans from your skeletal lover. You felt like you were filled with fire - fire that you knew would be blue.

As you gently jerked Sans off, he unbutton your jeans and slipped a hand inside. Your heart skipped a beat inside your chest as he reached inside your tiny panties, his finger running the length of your slit. The high moan that left your mouth encouraged him as he then started to play with your clit, his bony finger rubbing it in gentle circles. At this point, he clapped his free hand over your mouth.

"Your moans are sexy as hell babe, but don't forget that we're not home alone." He warned, not removing his hand from your pants. Gently, he circled your hole with one finger, and then two, before firmly inserting them inside you. You breathed hard against his hand as pleasure crashed through you. He matched the rhythm you were using on his hard cock as he finger-fucked you, slowly gaining in speed as the two of you got more aroused. As he continued to pound his fingers inside you, you felt him gently use his thumb to rub circles on your clit - causing you to bite down on the hand he had over your mouth. Jacking him off faster and faster, you used your free hand to tear his hand away and kiss him roughly. He moaned gently into your mouth.

"Fuck, I'm close." He gasped after a few seconds, "Are you? God, this feels so good. I can't get enough of you - "

"I'm close too." You cut him off, barely able to talk. You could feel the waves of orgasm build up inside you as he ruthlessly pleasured you, his fingers working magic. It was hard to think about anything but his cock pounding hard inside you, his glorious frame over you, touching you, satisfying you -

"Fuck!" He cried out, looking at you desperately. "Please, come now, please come now..." He said under his breath, as his hand suddenly increased pace tenfold.

"Sans!" You moaned, as you came. You clenched your eyes tightly shut as you lost focus on pleasuring him, ecstasy shaking to your core. Your whole body tensed as you shook, the intense euphoria taking a hold of you. Against you, Sans gasped your name and you felt hot liquid jetting onto your stomach as waist. He collapsed onto you as you both tried to regain your breath, his own pants ragged and exhausted.

"That... was amazing. How are you so good at that?" You smiled, looking at him. He briefly held his head up to meet your grin, before burying his face into your shoulder again.

"If I say 'internet research', can we still pretend I'm cool?" He mumbled. A small laugh escaped you.

"Yes, we can. Everyone learns somehow." You assured him, a sense of bliss washing over you. Nothing could ruin this now.

"ONE MINUTE LEFT!" You heard Undyne yell through the door.

"Fuck. Fuck fuck fuck." Sans swore under his breath.

"I didn't realise she was _actually timing us_." You complained, looking at Sans.

"Come on, clothes on, they can't catch us like this!" He hissed, bending down to pick your shirt up.

"Um, Sans?" You said, looking at the small mess he'd made on your stomach. "How am I going to get rid of that?" He only grinned at you, before a strained expression passed over his face. In the blink of an eye, it was gone.

"What?!" You incredulous questioned. "How?!" Sans only continued to grin at you.

"Magic." He laughed. "Now get your clothes back on."

 It took what felt like forever to redo your bra, before reluctantly pulling your shirt back over your head. Neither of you spoke as you hurried to get dressed again. It wasn't long before you heard the lock scraping, and then Undyne ripped the door open, the light of the outside world blinding you both.

"Wow." She laughed, eyeing you carefully. "Nice hickeys."

**Notes for the Chapter:**

> Thanks for reading! I know you guys waited a long time for this. XD  
> As ever, feel free to leave a comment below, send me an ask on my tumblr underblogger.tumblr.com , or tag a tumblr post with #UBTIAS :)


	13. The Aftermath

**Notes for the Chapter:**

> Sorry for the week-long gap in uploads! I had a little writers block, but hopefully I should be able to get back into the swing of things now!  
> A little warning - this chapter contains a buttload of speech!

As you followed a giggling Undyne back to the living room, Sans shamefully in tow, a million curse words shot through your head. If only you could get a look in a mirror, maybe take a look at whatever hickeys Sans had made, maybe they wouldn't be so bad?

"Heeeey!" Alphys drunkenly called as you entered the room. She held her bottle in the air and leant back so far she ended up falling over, before collapsing into another giggling fit. On your sofa in the far room, Mettaton was passed out of Papyrus' lap whilst the skeleton tried to eat his spaghetti. You couldn't fathom how it had turned out like this when you'd only been gone 7 minutes, but clearly leaving the lightweights with an alcohol-pusher had not been a good idea. What was worse was that Mettaton was totally out of it, but the only person that could fix him was currently drooling in a laughing fit on the floor.

"And I thought we were the messy ones..." You heard Sans mumble behind you. You would've laughed if you weren't concerned about someone being sick on the carpet.

"Okay... maybe this is the party limit." Undyne said, before walking over to Alphys and swiping the bottle out of her hand. A feeble protest escaped her before she seemingly fell asleep.

"Hey, do you guys want to just stay over? I'd be worried about you taking them both home in that state, in the city at night." You offered, slowly starting to pick up cans. Undyne turned to you to gratefully nod.

"That would be great, actually. We'll just sleep on the sofas, if that's alright?" She grinned, sweeping a very drunk Alphys into her arms - marital style.

"Yeah, that's fi- oh!" You cried as you were lifted into the air.

"And WE'LL sleep upstairs!" Sans said, scooping you up in the same way. He laughed before balancing half your weight on his waist, using his free hand to scoop up cans of cider into his pockets. He didn't wait for you to reply and simply walked upstairs still holding you.

-

"Hey!" You exclaimed as Sans dropped you on your bed. Whilst you scrambled into a comfortable sitting position, he clambered on next you, pulling two cans from his pockets.

"Let's play a game of our own." He grinned, handing you a can. "We take in turns to tell each other a statement. The other person has to guess whether it was true or false. If they're right, the other drinks. If they're wrong, they drink. Get it?" Confusion swept over you.

"I... I think so?" You said, frowning. Sans chuckled and a hiss cut through the air as he opened his can.

"Look, you'll get it. I'll start. Uh, I find you attractive." He blushed a little, glancing at you.

"Well that's definitely true, judging by what just happened." You smiled. He nodded, before taking  large gulp of his drink. "My turn then... I find you attractive too!"

"Hey!" He said, turning to sit facing you. "That's cheating, you can't just steal mine!"

"Fine, fine! Then, that was my first time touching a magical glowing dick." You laughed, as Sans snorted with laughter.

"True. Minx." He said casually, before lifting your can to your mouth. "Drink. Also, I have a pun fetish." You almost choked on your mouthful of cider.

"That's not true!" You laughed, throwing your head back. He was cracking up too, deep rumbles of belly-laughter.

"It's true! They turn me on!" He protested as you gently slapped his arm.

"That is _not_ true and you know it!"

"Yeah, fine, fine. My real one then... Aha!" He shuffled a little closer to you. "I prefer ass over tits."

"False!" You declared almost instantly. He looked a little startled.

"How did you get that so fast?" He gasped. You giggled a little, enjoying his surprise.

"I saw your face when I took my bra off, and it was not the face of someone who would prefer an ass." He looked sheepish as you spoke, a feeling of pride bubbling inside you. He slowly took a drink, keeping eye contact with you, before you shuffled closer to him. By now you were both sat cross legged, facing each other, with your knees gently touching. "I kind of hope that we'll play seven minutes of heaven again sometime." You admitted.  Sans took a long look into your eyes.

"That's true. But then again, so do I." He grinned, a glint in his eye as you took a drink. "Sometimes I picture you walking around with no panties... when I'm _alone at night_." His voice was husky and deep. You were glad you weren't standing up, because your knees were weak right now.

"That's gotta be true." You breathed, almost to yourself. Slowly, a shit eating grin spread across Sans' face as he took another swig from his can, before easily crumpling it in his hand and fetching another out of his pocket. A hot wave of arousal ran through you as you pictured Sans alone in his room, touching himself whilst thinking about you. You almost forgot he was sat right in front of you as you nearly lost yourself in the image. "Oh, um, my turn!" You suddenly squeaked as you remembered where you were. Sans only chuckled in response, his dark eyes not leaving yours.

"I threw that big party a week or so ago _just_ so I could dress sexily in front of you." You admitted, the alcohol fuelling the bravery of the comment.

"Is.. is that true?" He asked, as if he was holding his breath. To answer, you simply took a drink. Sans punched his fist into the air. " _I knew it!_ I _knew_ that was why you were dancing like that, and dressed like that! I knew it!" You could only blush, feeling somewhat naked as the truth started to come out.

"I deliberately chose to watch a horror movie with you so you'd get scared and snuggle up to me." He said, smirking at you.

"That's cute, and also true." You declared. He grinned and nodded, before chugging his cider. Another can was crushed in his hand and replaced with another from his pocket. It was almost ridiculous watching him, with the combination of how fast he drank and how many cans he had fit into his pockets making the sight comical. "I want to have sex with Mettaton." Sans growled at your words, almost bursting the can in his hand with a sudden tight grip.

"That's not true." He said through gritted teeth.

"No, it's not, but it's fun to watch you get riled up so easily!" You giggled. He face palmed as you grinned devilishly at him.

"It's not funny!" He protested, with the mood of a small child in a tantrum. You leant forward to pat him on the shoulder, your touch seeming to calm him down. "Okay, my turn... I like to be _in control_." Sans said suddenly, looking straight at you. Arousal crashed through you again.

"I... uh... I hope that's true." You stuttered. He'd caught you off guard. Wordlessly, he took a long drink out of his can before looking back at you once more.

"You look like that had an effect on you." He observed, smugness plastered all over his face. Alcohol simply caused you to giggle at this, leaning gently forward into him, resting your head on his chest. You were a mess right now, all thoughts of playing hard to get and trying to tease him completely out of the window. You were simply thoroughly enjoying this moment, that you got to spend alone with him.

"I really like you." You said, the words spilling from your mouth before you could stop them. As soon as you said it, you regretted it. Sans stiffened underneath you, before he pulled away slightly.

"That's true." He said, curtly. His voice was flat, unfeeling, and he slowly started to get off your bed as he took the can out of your hand. "You're drunk. Maybe you should go to bed now." He continued, as if scolding a small child.

"Hey, no wait!" You slurred, clambering after him. You couldn't let him just walk away this time. Grabbing his bony arm, you spun him around to face you. "Don't run away. I'm sorry I said that. Can we forget it? It's okay if you don't want to make this a thing or whatever, some people are afraid of commitment and - "

"I'm not afraid of commitment. Go to bed." He replied coldly, turning away again. Drunken tears of frustration filled your eyes as he started to leave. _You'd been having such a good time, of course you had to blow it, you were such an idiot..._

It took a few seconds for you to realise you'd started crying, but by then Sans had already left. You were alone. Your reflection caught your eye as you turned to look for him, and you furiously spun round to look at yourself in the mirror.

Fury filled you to the core as you started at yourself. _You'd ruined it all. Why did you always do this? Why wouldn't he just tell you what was going on?_

_At what point did you start caring for him this much?_

Alone and upset, you curled up in a ball and wept.

**Notes for the Chapter:**

> I'm sorry, it ended so sad!!! It will get better, I promise!
> 
> Thanks for reading! As always, feel free to leave a comment below, send me an ask on my tumblr underblogger.tumblr.com , or tag a tumblr post with #UBTIAS ! You guys are the best :)


	14. Putting Him Out Of Your Mind

**Notes for the Chapter:**

> Hello friends!
> 
> This chapter is pretty long, but I didn't wanna split it up!
> 
> Also, to those of you who may get agitated at the direction this chapter is taking - just know that it's all part of my master plan.
> 
> Mwahaha!

You spent the weekend mostly on your own, ignoring various calls and worried texts from Undyne and Alphys, who you'd only told that Sans had upset you, but not to the full extent. Papyrus would occasionally come into your room to say hello, but you didn't leave it often. You didn't want to accidentally see Sans somewhere around the house. You felt like he didn't deserve your company, and would only be acting like nothing had happened anyway. As if nothing was wrong.

The following week of work was tiring, but in truth you were grateful for the distraction it gave. You followed pretty much the same routine every day, but occasionally you would find some more of your underwear hidden in forgotten places around the house - which would only make you think about Sans more. As the days passed by, you felt yourself becoming less hurt over Sans' rejection and annoying behaviour, and more angry and frustration towards him. _Why did he behave like that? Did he think you were going to just lie down and let him treat you like shit?_

On your lunch break on Friday, you phone rung for the millionth time that week, but this time you finally decided to answer.

"BUDDY!" An excited voice yelled down the phone. "You answered! Are you okay? You haven't been talking to anyone. We're all so worried! How are you doing? Have you spoken to Sans?" The sheer amount of questions she flung at you made you wince. You felt bad for having kept her in the dark about the situation, but in order to tell her what he'd done, you'd have to tell her about the whole story - and you didn't know if you were ready for that teasing.

"Look, do you wanna come to mine after I've finished work? Say, 5 o'clock?" You asked. You knew you didn't have the time right now to properly tell her the whole story, and she probably deserved the full truth.

"Sure, I'll bring Alphys!" She excitedly said. You could practically hear the grin in her voice. With that, you hung up the phone and stood still for a while, trying to think about what you were going to tell her. Over the rest of your day, you slowly planned out your whole speech for the both of them. It meant that you were pretty distracted from your job, but on a Friday nobody was paying much attention either.

When you arrived home from work at 4:30, Undyne was already waiting in your kitchen with Alphys, making herself a cup of tea. She only grinned when you arrived, reminding you that Papyrus had given her a key to your place ages ago, and comforting a very nervous and apologetic Alphys.

You sat down at the table with them, all with various hot beverages, and began your story. You started from the very beginning, and your meal at Grillby's with Sans, through to planning and having the party - the part they already knew - and continued to the film, his stealing of your underwear, you hiding the porn inside his reports, and finally up to what had happened the previous week. Upon hearing his reaction to your drunken confession, Undyne got angrier and angrier, until she stood abruptly upwards, a cyan spear in hand.

"The bastard! He can't treat you like that!" She exclaimed, her eyes darting angrily around the room, as if she was daring him to suddenly appear.

"Undyne! Sweetie!" Alphys desperately cried, clinging to her in a weak attempt to calm her down.

"It's okay!" You tried to assure her, growing more and more fearful of her attacking your kitchen. She looked down at you and growled.

"It's not okay. You deserve someone that loves you, and treats you right!" The spear suddenly dissolved in her hand, and she dropped it to ruffle the top of Alphys' head. "We're gonna find you someone that will treat you right!"

"Oh, no, I'm fine!" You said eagerly. You really didn't want to be hooked up with some random guy you didn't know - every blind date you'd ever went on had gone terribly.

"You're n-not fine, ____." Alphys quietly remarked. "Your eyes are sad, angry and betrayed." She added, twiddling her fingers together. Her comment put a lump in your throat. _You weren't heartbroken. You didn't want them to pity you. You didn't want to give Sans the satisfaction of being someone being heartbroken over him._

"I have a plan!" Undyne announced, happily. She jabbed a scaled thumb into her chest and grinned down at you, the pose reminiscent of an anime character. "We're gonna take you out! We have an extra ticket!" Your stomach dropped in alarm.

"An... an extra what?" You carefully questioned. She laughed, loudly.

"An extra ticket to Mettaton's play tonight!" She said, her grin revealing her sharp teeth. "Come with us! He's even invited us to come to the after-show party!" You continued. You didn't have time to say anything, Mettaton's name constantly ringing around your head. As Alphys started to tell you how good the ratings of his performance in the original piece had been so far, the memories of his kiss flooded back to you. You couldn't hide it from yourself, you had guiltily enjoyed it at the time, and clearly so had he...

"Hey! ____! You in there?" Undyne called, waving a hand in front of your vacant face. "Wanna come, then?" She asked. You considered it for a second. At the very least, it would be better than being alone all evening.

"Uh, sure!" You smiled, mustering up enthusiasm as memories of Mettaton's drunken, possessive  smile washed through your mind.

Papyrus arrived home as they went through the evening's plans with you fully, and you all talked about it over a meal of spaghetti bolognas. Like any plan made by Undyne and Alphys, it was fairly last minute as it turned out the play was that night. Apparently Mettaton had simply given them 4 tickets 3 days ago and beyond Papyrus - who was allegedly brimming with excitement about it - they hadn't gotten hold of a fourth person to come with them.

When you started to get ready upstairs, you heard the front door creak open and close underneath you. Clearly, Sans had arrived home. Nerves coursed through you a little since you hadn't spoken to him, or even seen him, since what had happened. However, you didn't really want to talk to him and decided to just stay in your room as you heard him briefly say hello to everyone downstairs. As you pulled your classiest black dress on, he began to climb the stairs. The dull thuds of his feet getting louder caused your heart to pound harder, and you tried to push the feeling down within you as you did your hair.

He seemed to stop outside your door for a second, the shadow he created underneath it giving him away, before he moved away, presumably into his room. It didn't take you long to finish your look by putting your makeup and grabbing a bag, and you confidently swept out of your room, ready to go out to the play.

When you left your room, you were met face to face with Sans. For a long time, neither of you spoke, both waiting for the other to say something.

"You've dressed up. Looks nice." He remarked, cutting through the pause. You looked away briefly as a blush of surprise threatened to pass across your cheeks. You weren't expecting him to compliment you like that.

"Um, yeah. I have. We're going out." You replied, somewhat nervously. You knew you shouldn't care, but you just prayed he didn't ask you where you were going.

"Oh, right. Explains why everyone's downstairs." He nodded, shuffling awkwardly from foot to foot. The two of you barely made eye contact. "Have fun, I guess." He finally said, shrugging. You knew it was probably meant to be nonchalant but there was something different behind his eyes that gave away his uncaring act. You really didn't want to delve into this right now, and he looked rather like he wanted to run away.

"Thanks. You have a good night too." You said, smiling gently at him. He smiled back at that, and a desperate feeling of longing came back to you. You just wished he hadn't behaved the way he had last weekend, if only everything could've gone okay...

"Hey, ____, you c-coming?" You heard a small voice pipe up. You turned to see Alphys halfway up the stairs, sheepishly staring at you. "Sorry, we've got to go now, or we'll be late." She added, looking extremely guilty for interrupting you and Sans. You glanced at him briefly, not wanting to abruptly leave the tentative conversation like this.

"It's okay." He said, showing he'd understood what your look meant. "You go. I'll probably go to Grillby's anyway." After speaking, he gently placed a hand on your shoulder and looked into yours for a long moment. It was as if he was searching for something, but cut it off by pushing you gently away. When you arrived downstairs, Papyrus was too busy excitedly rushing you all out of the door for Undyne and Alphys to question you on what had just happened.

It didn't take you all long to walk to the city theatre, but you certainly regretted wearing high heels, as it made it extremely difficult to catch up with an over the moon Papyrus. When you arrived, it was revealed that the tickets actually gave you a seat in a very fancy box with a great view of the stage. You were surprised at first, but considering Mettaton's generous nature towards Alphys, it only seemed normal after a while. The play enraptured you from the very start - with tonnes of highly skilled dancers starting the performance with a very over-the-top routine. You had been told earlier that Mettaton himself had been given a big part in the writing of the play, and this showed through with the glamour that ran through every scene, every piece of set and costume, and every character. Mettaton himself turned out to be a great actor in his scenes, with the excellent ability to mix melancholy with humour. He also had a great vocal range and was a natural dancer, but you had known both of these things already. In the interval, you all only talked about how much you were enjoying it and waiting to see what happened next, and when it ended the whole theatre gave it a standing ovation. You almost wished it had been a film, so you could see it over and over again.

As you waited in the lobby afterwards, a loud voice called from behind you all.

"Darlings!" A male voice cried as you all spun around.

"METTATON! YOU ARE MY _FAVOURITE_! MAYBE YOU SHOULD HAVE MY TITLE OF BEING GREAT!" Papyrus immediately called in return. As the four of you walked over and began gushing compliments, he simply stepped back and shook his head.

"Now babies, remember it wasn't all me. I had help from my other cast members, and the crew as well." He smiled, taking it all in his stride. "Actually, speaking of, want to come with me? I can take you to the party."

It turned out the party was in a fancy bar just across the street, and all the cast and crew were there. Several people looked vaguely familiar from soap operas you didn't watch, but mostly people seemed to have their own friendly groups. It didn't take long to find a table for the four of you, and Undyne began by going to the bar to get everyone a fizzy drink to start with.

"Ah, we're not having alcohol tonight?" Mettaton asked, smirking at you.

"Hey, you're the one who's always more drunk!" You exclaimed, trying to defend yourself. Alphys laughed gently from across the table.

"Yeah, blame me for that. I can never get the wiring just right. Either he's too drunk, or not enough." She grinned, the robot and her exchanging a knowing look. When Undyne arrived back at the table and passed the drinks around, she grinned at you madly. You were confused as to why until you realised she was constantly looking between you and Mettaton sat next to each other. You could only desperately scowl at her in response, trying to subtly get her to stop being so obvious that this had been her plan all along. Clearly, she'd never wanted to set you up on a _blind_ date. _What was it with Undyne and playing matchmaker?_

After an hour or so of her grinning madly whenever you and Mettaton even glanced at each other, she eagerly grabbed Papyrus and Alphys, dragging them to their feet with her.

"Let's go to the bar!" She cried slowly, pulling them along. As they tried to resist and failed, you could hear them faintly protesting in confusion as they got further and further away. Mettaton only looked amused, but showed no signs of realising why she'd done that.

"So how have _you_ been?" Mettaton purred once you were alone. His eyes may be robotic, but they had that same look of seduction and confidence in them that you'd seen in Sans' eyes before. After thinking it, you scolded yourself for thinking about him at a time like this.

"I'm er... I've been good. What about you?" You said, cringing at how awkward that reply had been.

"Very well indeed." The robot replied, enunciating every syllable. He leaned closer towards you, and out an arm around your shoulders. "I'm glad you're here. I _do_ hope you're having a good time."

"It's great! I really enjoyed the play, too." He swelled at your compliment, and you could hear the fans inside his chest plate whir harder. In the dim, yellow light, it was hard not to marvel at Alphys' handiwork. His features were perfectly crafted and extremely precise, as well as Mettaton's own additions - such as black lipstick, eye shadow, and perfectly drawn eyebrows - all combining to create this god-like image of what sexy should look like. Intrusive thoughts about his kiss flooded your mind once more. Maybe your remark to Sans about having sex with him hadn't been a lie after all.

 _Damn it!_ You suddenly thought. _Every time, Sans always comes up! Can't I get him out of my head?!_

"Hey." A gentle voice cut through your thoughts. "Did you hear what I just said?" Mettaton asked, looking concerned. You blushed, having been caught out drifting off into thought.

"Sorry, I didn't." You admitted, sheepishly. The robot only smiled knowingly, seemingly not offended by it.

"I said, do you want to come to dinner with me sometime?" He confidently repeated. Your mouth went dry as your mind stalled over his question.

"Like, a date?" You stupidly said, struggling to stop your mouth from hanging open in surprise and shock. He laughed, gently.

"Of course, like a date." He confirmed, gently holding your chin in his hands. He leaned your head up to look into his eyes. It felt weirdly familiar.

"Oh, um, yes." You stuttered, not really thinking about what you were saying as his sexy facial expression stole away your rational thoughts. "Sure." Mettaton grinned somewhat triumphantly in response.

"Perfect."

**Notes for the Chapter:**

> Thanks for reading! As always, feel free to leave a comment below, send an ask to my tumblr at underblogger.tumbr.com , or tag a post with #UBTIAS !


	15. Robots Can Eat At Dinner Dates

**Notes for the Chapter:**

> Hello! This is late and a little short! I am sorry!
> 
> Also, it's come to my attention that I'm shit at spellchecking - so if you see a mistake I am gravely sorry and I do want you to point it out to me.
> 
> Hope you enjoy!

It was the following night, a Saturday night, when you had arranged to have your date with Mettaton. Since he was so busy, and didn't get nights off very often, he had been eager to meet as soon as possible. This was good for you, considering that the more time you spent around other people, the less time you spent moping or going back over everything that had happened. It was time to put it all behind you.

You were stood waiting by the door for Mettaton, who had insisted on coming to pick you up - even though the restaurant was only a short bus ride from the house. You knew it was sweet, but you also felt slightly nervous. The fact that you were all dressed up and ready only made it worse that you couldn't help when your date got here. You were a little powerless.

 _Although_ , you thought as you looked into the mirror opposite you, _you did look damn good._ You'd tried especially hard with your outfit, even down to wearing your favourite underwear. Every part of you was polished and perfected.

Just as you thought this, you heard a rumbling noise outside the house. Without thinking, you instantly stepped out of the door - which, when you thought about it, made you look a little eager. However, these thoughts were washed away when you saw the vehicle in which Mettaton had arrived - a shiny black limo was parked on the street outside.

"DARLING!" You heard Mettaton call as one of the doors was flung open. "You're all ready and enthusiastic! I love that!" He opened his door wide and gestured with a flick of his wrist that you should get in. Still in shock, you only grinned and obeyed. You knew it would be very embarrassing to arrive at the restaurant like this, but at the same time you were fully prepared to enjoy this grandeur whilst it was available to you.

Once inside, you couldn't help feeling a sense of wonder. All the upholstery was soft black leather, along with tinted windows that made you feel just as famous as the robot that was climbing in next to you. Mettaton called to his driver - who was hidden by a partition - to set off, before handing you a glass of champagne from a small bottle stored in a compartment in front of him.

"Cheers, dear." He confidently said, clinking an empty glass to your own. "Tonight is all on me." You took a small sip, before smiling sweetly at him.

"Mettaton, honestly, you don't have to - " You tried protesting, but he only cut you off with a wave of his hand.

"I know I don't _have_ to. I want to." He replied, giving you a brief caring glance, before leaning back comfortably in his seat. He looked so at home in this environment, but you'd had no idea that he was regularly living this fabulously. It was simply amazing. You took the time to look at him properly, and admired the way that he'd also tried hard to look good for you. His usual bright pink boots were replaced with black ones, and his chest plate was an alternate version that had a shirt and tie on it.

It didn't take long for you to arrive at the restaurant, and when you did you were a little upset that you would have to leave the limo. As Mettaton exited the car, and then walked graciously around to open your door for you, you heard several gasps and giggles as people on the street recognised who he was. It was a little daunting, to say the least.

"Don't worry about them." He gently said to you, as he opened your door and held a hand out. After you gratefully took it, he helped you out of the car and led you to the door.  It didn't take long for the both of you to be seated towards the back of the restaurant - but still able to look out the windows - and your waitress handed you a menu.

"So..." You started awkwardly, gesturing to your menu as you spoke. "How will this work?"

"Alphys has really pulled a number out tonight!" He replied excitedly. "I'm going to be consuming a specially prepared mix of silicone lubricants and other such substances!" His joy at being able to emulate eating a meal the way a biological being would filled you with a warmth you couldn't describe. It was lovely to see him so happy about it.

Your meal started off very well. The waitress served you endless amounts of the nicest wine you'd ever tasted, whilst Mettaton breezily talked about Alphys' new calculations on getting him 'drunk'. This time it was going to be the right pace, he assured you. During the conversation, you could only laugh a little as you thought about the past experiments she'd had - including an image of the robot drunkenly passed out in Papryus' lap.

When your food arrived, Mettaton was handed what looked like a bowl of flavourless jelly. To be honest, it looked completely disgusting, but the TV star was clearly over the moon about it. You could only watch in nervous anticipation as he lifted a spoonful of it to his lips. You really wanted this to work out. He carefully licked the whiteish-clear substance from the spoon, before taking a long moment to consider it. You held your breath.

"It's delicious!" He cried, clapping his hands together in delight. "Oh, I love it! I love it so much!"

"Brilliant!" You instantly replied, just as excited as he was. You knew that this was an important breakthrough for him, seeing as being able to fit in with humans was one of his greatest joys since he had come to the surface. Whilst he loved monster kind, and thoroughly aimed his shows to entertain them first and foremost, that didn't quell his ever-growing love of humanity.

"Yes..." he said thoughtfully, before a devilish grin spread across his face. "Now I can really _eat out properly._ "

You weren't sure whether he was joking or not, but a heavy wave of arousal ran through you. His statement had totally cut through his gentlemanly act like a knife, and it left you speechless. _What on earth were you meant to say in response now?_

"It seems that I caught you off guard. I apologise if that was too rude." He amended gently, his eyes big and full of concern.

"No, that was just..." You tried to act casual, but it wasn't working. "It put a pleasant image in my head." You finished, feeling brave. Upon your comment, Mettaton raised a perfectly angled eyebrow and his same grin returned. Clearly, the drunkeness was getting to both of you.

"Clearly you are not as innocent as I had pinned you down as." He said, his eyes hungrily searching yours. You nearly laughed out loud, thinking about all the events of the past few weeks with Sans. Memories of walking through the city with no underwear, nearly getting Sans to show porn to the king, and jacking each other off in a cupboard flooded through your mind. Nevertheless, you managed to push Sans back out of your mind as you composed yourself again.

"I think everyone has secrets, and other sides to them." You smoothly replied, trying to calm the situation somewhat. After all, having kissed or not, this was still the first date - even if you'd known him for a long while before this.

You managed to steer the conversation towards Mettaton's acting career, which was always a safe subject. He could talk for hours about the various shows and plays that he was in, as well as how much he simply enjoyed acting itself. It was great to hear him talk about something that he was clearly so passionate about, and something he clearly enjoyed doing so much. The more you talked with him, the more comfortable you felt around him. He was very easy to converse with, and was also very good at finding new things to talk about. Either it was the wine you'd been drinking or the way he was smiling at you, but you were feeling something you hadn't felt in a while.

When you'd both finished eating, a waitress meekly came over and started smiling inanely at your date. He didn't seem to notice this, and casually asked for the bill.

"So darling, I was thinking, do you want to go somewhere after this? I can get my driver to take us anywhere we like, you know." Mettaton drawled casually. He started listing a few possible places as something out of the window caught your eye. You were only half-listening as you stared over his shoulder, trying to locate whatever you'd just seen. It only took you half a second to see it again.

There, stood outside the window, was a pale face watching you at dinner with Mettaton.

Your heart stopped.

It was Sans.

**Notes for the Chapter:**

> Hahahaaaaaa!~  
> You should all know my heart was pounding super hard when I wrote the last part, even though I knew what I was going to write. Next chapter is going to be a big ole ball of fun to write, I can tell you that for free.
> 
> thanks for reading! As always, feel free to leave a comment below, send me an ask at underblogger.tumblr.com , or tag a tumblr post with #UBTIAS


	16. Mettaton Pays The Bill For You

**Notes for the Chapter:**

> Ugh this was so hard to write! I'm sorry it's a day or so late, but I got a tonne of work laid on me this week!

Shock. Confusion. Anger.

The only three emotions you could process ran through your head as you stared back at Sans in shock. You couldn't believe your eyes, and you also couldn't believe his audacity. Anger and shock fought violently within your head as your hands started to tremble. You didn't know whether you were sorry or triumphant.

Trying to reason with yourself, you took a deep breath. Clearly, Sans had just been passing by and had happened to see you, but the thought of him watching you deliberately wouldn't leave your head. It bubbled up inside you, a torrent of emotions you couldn't quite place and the itching feeling you should be doing something, acting upon this, confronting what was happening.

"Darling?" Mettaton's soft voice dragged you out of your trance. You barely turned your head away, quickly flicking your eyes in his direction.

"Sans." You managed, his name almost catching in your throat. Mettaton looked throughly perplexed at what you'd said, and a passing look of concern crossed his face.

"What? Are you okay? You look like you've seen a ghost." He said, placing a gentle hand over your trembling one. You only gulped and nodded in Sans' direction.

"Something like that." At your words, Mettaton turned and stiffened up. Sans made direct, furious eye contact with him. A long silence occurred where nobody dared to move, and nobody dared to speak. Panic started to rise in your gut. One deep breath. Two deep breaths. Three...

"I'll go talk to him." You said firmly, standing up. Your robotic date turned swiftly back around to look at you.

"Are you sure? I can deal with him, darling. He shouldn't bother us." Mettaton assured you, not having let go of your hand as you looked down at him. His cold annoyance at the skeleton was masked under a look of what could only be described as apologetic, but at this point you'd gotten a hold of yourself again. You were feeling brave.

You smiled down at him, squeezed his hand, and then started to make your way over to the door. A part of you almost wanted the journey to take longer than it did, but in reality it only took you all of 10 seconds to cross the busy room and push through the open door. The cold air hit you in the face, it's bite making you regret not grabbing your coat, but you knew that you couldn't let it bother you. You were filled with determination.

When you crashed through the door and turned to look at him, Sans' eye sockets were empty, the pitch black telling you exactly how he was feeling. In his hand, he was clutching a small white carrier bag, and he was only wearing his usual sweatpants shorts and a blue coat - he'd only been going to the shop when he'd walked past. He opened his mouth to speak, but you cut him off.

"What the hell are you doing?" You bluntly asked. He almost look shocked for a second, before his jaw steeled and the angry grimace returned.

"I could ask you the same question, going on a date with _him_." He growled, refusing to even speak his name. At the back of your mind, a small voice told you he was being petty.

"And?" You swiftly replied. He looked briefly confused - you'd caught him off guard again.

"Uh.. what?" He said, slowly.

"Is it any of your business that I'm on a date with Mettaton?"

"It's fucking _Mettaton._ What the fuck are you doing? You're all dressed up for _him_ , coming out to this fancy restaurant with _him_..."

"Why are _you_ bothered?"

"Oh, so nothing between us meant _anything_ to you?" He raised his voice a little at this, and the words cut into you. You weren't sure how to proceed. He'd actually acknowledged that you'd had something different, special, and he'd done it whilst you were on a date with another man.

You didn't want to think about that too much. You were determined to not show him any weakness.

"I didn't think you cared, after what happened last week." You replied. He shook his head, a look of angry disbelief crossing his features.

"What? What last week?" He questioned. The fact that he didn't even remember fuelled your anger again.

"Oh, so you _don't_ remember rejecting me and leaving me alone crying?" Sans looked somewhat taken aback, and the pinpoints of light returned in his eyes.

"You were crying?" He asked, quietly. You were amazed he hadn't noticed, and furious he hadn't bothered to stay long enough to see it either.

"Yes, I was crying. I admitted something very private and important to you, and you immediately dismissed me, stopped talking to me, and left. Plus, not only was I drunk when I said it - so my emotions were volatile anyway - but we'd also just done something personal. And, I stupidly thought, meaningful." You snapped. He looked a little taken aback at what you'd said, and he stepped forward, condolence plastered all over his face.

"Don't apologise. I don't want your pity. It took me a little while, but I'm over it now. Clearly." You added, making very obvious glances towards Mettaton, who was currently paying the bill at your table.

"So what, you got your feelings hurt and you're on the rebound with some arrogant jerk?" He suddenly spat, venom in his voice. His sudden transition from ashamed shock to cutting anger hurt a little.

"It doesn't count as a rebound when you didn't have a relationship because _ONE_ of the people were ridiculously and _childishly_ unable to talk about their feelings properly!"

"So what, as soon as I reject you you're so _desperate_ you go for the guy I hate? What's up with that?"

"At least I'm not so desperate and perverted that I steal someone's underwear."

"You threw a _whole fucking party_ to impress me!"

"Yeah, well I wish it had been worth it, but clearly it was the biggest waste of time in my life. All of it was." At your words, Sans suddenly looked sad. There was a long pause.

"You... you think it was all a waste of time?" He almost whimpered.

"Look where we are now." You pointed out. Something changed in Sans, and he started to turn away. As he buried his face into the fur-lined hood of his coat, you swore you could see tears form and drip down his face.

"Whatever." He said quietly, all the energy gone. You weren't sure what to say.

"Sans - "

"I didn't feel anything either then!" He suddenly bawled at you, lifting his face out of his coat. Thick tears were running down his face, and he wiped them away messily with the back of his hand. "If this is so meaningless I'll just leave. Have a good night." He took one last look at you before turning around and walking quickly away. As you stood in shocked silence, you could hear gentle sobs and sniffs as he turned a street corner and disappeared from view.

A large lump formed in your throat. Sickness churned in your stomach. However, your head was full of memories of the times that _you'd_ cried over _him_. He hadn't run after you then - or even recognised it.

It was a relief when you felt a soft hand on your shoulder.

"Are you okay, darling?" Mettaton asked. You turned to face him, and he handed you your bag. It was very sweet that he'd thought to get it for you. Mettaton was always a gentleman, unlike Sans.

"Yeah, I'm okay. Thank you." You smiled gratefully. The TV star nodded, relieved, before affectionately placing an arm around your waist.

"You're in control of the night, sweetheart." He reminded you, jolting you into thinking about what you wanted to do now. You didn't want to go home in case Sans was there, but being in public didn't seem any more appealing to you.

"Is it okay if we just go to your place?" You questioned. He seemed startled, but eventually beamed down at you.

"Sure thing, beautiful. Let's find the car."

-

Neither of you spoke much in the ride home, aside from comments about the restaurant and the food. You felt bad that you'd ruined the big night where Mettaton finally got to "eat food", but part of you blamed Sans as much as you blamed yourself. You also weren't totally surprised to find out that your robotic date lived in the penthouse suite of one of his own resorts, in the city centre. Burgerpants nodded shyly at the both of you as you walked in, but you weren't paying much attention to your surroundings. You couldn't get that argument out of your head.

The second the two of you stepped into Mettaton's apartment, you pulled him somewhat roughly into a kiss. He was stiff for a second, but easily relaxed into it. You hooked your arms around his neck and he responded by wrapping his around your waist. You stayed there for a short while, faces pressed hungrily against each other, whilst Mettaton kicked his door closed behind you. He was better at this than you remembered, but it probably helped that you didn't have a room full of people watching you this time.

Swiftly, he picked you up and carried you across the room, settling you both on his sofa. You didn't see much of the room around you - since you were pretty occupied - but the material was soft, and it was so plush your bodies sank into it easily.

As his tongue continued to explore your mouth, you gently pushed him backwards. He landed softly on his back and he parted from you for a second to register where he was, before pulling you close again. He kissed softly along the line of your jaw, before gently biting and sucking on your neck. You moaned slightly, trying to simply bask in the pleasurable feeling.

However, your mind was still whirring at a hundred miles an hour. As he kissed your neck, all you could think about was how Sans had done that very same thing. You couldn't help but compare their touches, the way they held you, the sounds they both made. Trying to push Sans out of your mind, you pulled one of Mettaton's hands up to your chest, allowing him to gently cup one of your breasts. He stopped kissing your neck as he gently squeezed, clearly intrigued by the sensation. His fingers drifted idly around the edge of your breast for a small second before he squeezed it again. Sans' skeletal hands drifted into your head once more.

"Kiss me." You commanded, and he complied eagerly. His lips enthusiastically met yours, and you tried to put the same energy into kissing him back. But, as you continued your make out session with Mettaton, memories of Sans kissing you filled your brain.

You ran your hands over Mettaton's metallic, heated chestplate.

You thought about Sans' ribcage.

You ran your hand through his jet-black hair.

You imagined brushing your hand over Sans' skull in the same way.

You opened your eyes briefly to remind yourself that you were kissing _Mettaton_.

You could only see Sans' crying face.

"I'm sorry." You said, pulling swiftly away. This wasn't working. You knew, deep down, that it was wrong to keep doing this if you were thinking about someone else. You needed to sort your head out before this ended up going too far.

"What's wrong?" Mettaton said, sounding worried. His never-ending amount of concern and care nearly brought tears to your eyes. You didn't want to hurt him.

"I think I should go home."

**Notes for the Chapter:**

> It's so sad!! I'm sorry. The angst won't be going on for much longer, I promise! It's all in my grand scheme.
> 
> Thanks for reading! As always, feel free to leave a comment below, send me an ask on my tumblr at underblogger.tumbr.com , or tag a tumblr post with #UBTIAS !


	17. You Get Answers

**Notes for the Chapter:**

> Sorry, this is a little late! I've had a lot on my plate lately :')
> 
> If there are any spelling errors, please please PLEASE tell me!
> 
> By the way, I'm super busy so I don't always get time, but even if I don't reply to your comment I want you to know I read them all over and over again. You guys are the best.

The car journey back home was quiet. You were too focused on what was going on inside your own head to notice what was really going on, and part of you felt bad for breaking off the make-out session like that. However, Mettaton was a gentleman, and even walked you up to your door.

Once you were inside the house, you heard loud, wracking sobs coming from upstairs. You gritted your teeth slightly and steeled yourself. It was time to talk to Sans.

Not even the sound of you climbing the stairs stopped the open weeping emanating from behind Sans' bedroom door. It was slightly scary - you'd never heard him crying, let alone crying like that before. As you neared his bedroom door, you hesitated for a second. You knew that you could just go to your room and address the issue later, but you also knew that if you didn't confront it now, it might wreck the very foundations of your relationship with Sans - even friendship might not be possible. You took a deep breath, before knocking on his door.

"Come in." Sans weakly sniffled. You gently opened his door, and peered into the dark room beyond.

"Sans?" You asked, taking in the state of his room. It was even messier than usual, with empty ketchup bottles scattered all over the floor, mixed amongst dirty clothes, packets of potato chips, and the occasional whisky bottle. The skeleton didn't say anything to you as you caught sight of him, curled up amongst a ball of sheets on his bed.

"Sans, I think we should talk." You gently said. He only nodded weakly, and dragged himself to sit upright. The sheets bundled around him made him look small and cute - a strange pain started to form in your chest.

"You've got to tell me what's going on." You finally said. A huge wave of nervousness went through you. This was it. You had to have answers. "I mean, one minute you rejected me, and then we went through this whole crazy thing, and as soon as I get sincere you reject me again - but you don't want me dating other men?"

"Look, ____." Sans began. "It's hard to describe, and I really wanna make it clear to you, but I don't know how..." He trailed off, staring at his hands for a second.

"Describe what?" You eagerly asked. You were so close, so near to finally getting something real from him. After a long pause, he looked you in the eye.

"I'm not like other monsters. My magic doesn't work in the same way. I'm dangerous, and I don't want to hurt you." He slowly said. You frowned at his words, completely underwhelmed. After all this time, Sans was just worried because he was capable of fighting people?

"Sans, all monsters can attack with their magic. I know that." You tried to keep the confusion out of your voice, and failed.

"Not all monsters can do what I can do."

"I don't understand. Don't different types of monsters have different types of magic?"

"I don't even think Papyrus would be capable of doing what I can do."

"Look, Sans, what on Earth are you talking about?"

Sans stood up then, and walked over to you. He held his arms wide open, as if he was reaching for a hug.

"Step into my arms. Hold tight and don't let go. I'll show you what I mean." He said. You were completely and utterly baffled, but decided complying was the only way you were going to figure this out.

As he held you in a tight embrace, you heard him mutter one last reminder to not let go, and then the world went black around you. You couldn't feel the floor beneath your feet anymore as the darkness swirled around you crazily, sucking away any signs of where you were in the room. Feeling sick, you tightly shut your eyes and gripped hard to Sans. However, as quickly as it had disappeared, the ground suddenly appeared beneath your feet again. You breathed heavily, fear gripping you, as you felt wind blowing harshly onto your sides. You tried to believe you were still in Sans' room, but a small part of you knew that wasn't the case anymore.

"Hey, open your eyes. It's ok. We're here." Sans gently said, releasing his grip on you. Slowly, you opened your eyes and looked around, before screaming loudly. You were stood on top of the roof of the town hall.

"How the fuck did we get here?!" You practically shrieked. Next to you, Sans flinched hard.

"My, uh... my magic. I can teleport." The pain was clear in Sans' voice. Clearly, your fear had been exactly what he'd been worrying about, and you'd just confirmed it for him. Regret for your stupid, unthinking reactions burned within you.

"I'm sorry!" You suddenly said, looking up at him. He was pointedly not looking at you. "I'm sorry, I shouldn't have reacted like that. I just... wasn't expecting that." You amended. He looked a little better, but not really that much.

"I'll take you back. Clearly, I shouldn't have told you."

"No, please! I'm sorry! I really, really want to know what's going on, Sans."

He regarded you carefully, before wrapping you in his arms. Without saying a word, you felt him clench around you, and the sickly blackness returned. You struggled through it, tried not to be sick, and found yourself back in Sans' bedroom.

"It's more than just... teleporting." Sans said, after the short silence that ensued. "There's more."

"Like what?" You gently asked. Sans strained a little, and his left eye suddenly started glowing blue in the familiar way you'd seen before. However, instead of having his usual reaction when you'd seen it before, you saw something on the floor glowing blue. With a flick of his wrist, three empty ketchup bottles flew across the room. You gasped, incredulous, as he then picked up a sock without touching it, letting it gently sit in the air.

"I can move things. Manipulate gravity. That sorta thing." He briefly explained, before frowning a little. One short second later, and the bed behind him lifted swiftly into the air.

"I... Uh..." You stuttered. No words could describe the amazement you felt. Sure, you'd seen monster do magic before, but nothing like this. No magic you'd ever seen even came close to this.

"If I'm scaring you, I can stop." Sans suddenly said, his face full of concern. You realised you'd been staring at him, open mouthed, for the past few minutes. All air-borne objects in the room came crashed down again as he took a small step towards you.

"I'm fine." You managed, trying to take it all in. "But... these amazing gifts... have they really been stopping you from carrying on with 'us'?" You asked, gently. Sans looked guilty, and shook his head.

"In truth, no. Come outside with me, there's something I should show you."

-

You shivered hard as you stood next to Sans, just outside your back door. He turned to face you, his face full of worry.

"Now, if you're scared after this, I totally get it." He said. His warning didn't really make you feel any less scared about whatever he was about to do. Slowly, Sans walked into the middle of your garden, and turned towards your garden hedge.

"There's a field behind this, right? No houses, no people?" The skeleton suddenly asked over his shoulder.

"Uh, yeah, it should be clear." You nervously replied.

Without another word, Sans shoved his hands into his pockets. There was a second of silence, before a large, canine-esc skull with a large crack down it's middle appeared above him. It's jaw unhinged, before a large white light spewed out of its mouth. The brilliant beam was blinding, and you had to shield your eyes a little as the colossal jet of pure white energy fired straight at your garden hedge. Once the beam disintegrated, you gasped.

There was a massive hole right where it had fired.

Sans, however, didn't take any time to regard the obliterated hedge, and bent slightly over. He was visibly shaking. Above him, another canine skull appeared. Then another appeared. In a flash, Sans had summoned about fifteen of the skulls above him, each as tall as he was and hung around 7 feet in the air. He turned wildly around to look at you, and the skulls turning threateningly.

"Look at me." He said, darkly. "I am what you humans would truly call a monster. Look at what I can do. This isn't even a challenge, I could summon twice, three times this amount."

Sweat beads started forming on his forehead, but he continued to talk.

"Gaster," He spat, almost to himself. " _He_ gave them to me, _he_ did this to me, and then poof - he's gone. In times of darkness and anger, ____, I can't control myself. They appear randomly and madly, and I can't stop that."

Sans started to get more agitated, and another skull appeared above his head.

"Why would you like me, a terrifying _monster_ , when you could date some nice, gentle human boy? He won't be able to do this. He won't be broken the way I am. I'm a freak amongst the freaks."

More skulls appeared. You felt strange. A small voice in the back of your head told you that you were scared of Sans, but you tried your hardest not to believe it. Sans threw his head back and looked at the sky.

" _Is this what you wanted, you sick fuck?! This is where experiments get you. This is what you do to other people!_ " Sans was madly yelling at the sky now. You started to worry about any neighbours that might see what was going on.

"Sans, please." You said, walking towards him. As you got closer, his eyes grew wider with fear.

"Don't come near me!" He cried, trying to step back. Desperately, you grabbed his hand and held it in yours.

"Sans, it's ok. It's ok if you can do things other people can't - even if you don't want to be able to do them. It's ok if the underground affected you, hurt you - whatever you're struggling with, I can help you through it. You can always just talk to me about this." You thought your voice sounded weak, feeble, but Sans seemed to calm down greatly at your words. You glanced nervously at the skulls above him. "Sans, I know you can get rid of those things if you want to." He followed your gaze and looked up at them, before looking down at his feet. Slowly, the skulls started disappearing one by one.

"They're called blasters. Gaster blasters." He quietly said, as the last one vanished.

"Gaster blasters?" You gently questioned, confused at the odd name.

"Named after W.D. Gaster." Sans said, miserably. "Named after my father."

You didn't even have time to question that, as Sans practically ran over to you and cupped your chin in his bony hands, tilting your face to look you in the eye.

"I like you, ____. I really like you, in _that_ way. But I'm dangerous, I'm scared, and I have more problems than Papyrus has spaghetti. I worry, about everything and anything, and the last thing I want is to drag someone so wonderful into my mess or even worse - get you hurt. You are... so amazing."

Before you could say anything, Sans pulled you into a desperate, needy kiss.

**Notes for the Chapter:**

> Thanks for reading! As always, feel free to leave a comment below, send me an ask on my tumblr at underblogger.tumblr.com , or tag a tumblr post with #UBTIAS !
> 
> PS: Any fans of Fairy Tail here, I've started writing a fanfic for it on this account if you wanna check it out :)


	18. Breakdown, Remember, Rebuild

**Notes for the Chapter:**

> YO! It's been a while, but I really wanted to perfect this chapter.

You tensed up immediately in shock.

Feeling this, he pulled away, but left his bony hands gripping your upper arms hard. He had a desperate, almost crazed expression as he looked you straight in the eye.

"Oh god, I'm sorry... You didn't want that, did you? I... oh god... I'm a piece of shit, I'm so sorry..." He rambled madly, tears uncontrollably streaming down his pale face.

"Hey, no, it's okay, please..." You tried to reassure him, but just ended up rambling back. He wasn't listening to you, his eyes darting around. Finally, he looked down at his feet for a second, before meeting your eyes again. His big, black eye sockets were totally empty.

" _I'M SO SORRY!_ " He wailed, before gripping you even tighter than before. Your legs nearly buckled beneath you as you were sucked into the pitch black void. You tried to cry out, to do anything, but before you knew it you were stood in his bedroom.

Sans yelled out incoherently, the most desperately sad sound you'd ever heard, as you started flicking quickly from place to place. You were in his room, and then outside Grillby's, then in the living room, you fell onto the sofa, you were stood at Sans' hotdog stand, then in your room, you crashed together onto one of the chairs in your kitchen, you were sat on your living room floor, then you found yourselves cramped into your airing cupboard, before you returned to your original place in the garden.

Instantly, you violently pulled away from him and fell to your knees, convulsing and retching. Sickness filled your mind, and you couldn't stop yourself from dry-heaving onto the grass as you heard Sans swear to himself.

"I'm so sorry... I didn't meant to - I'm sorry, I just - "

"It's okay." You tried to comfort him, through gags. "I'll be okay. Just not used to that." After a minute or so, you could finally breathe again, and you looked over to see Sans with his face in his hands.

A large Gaster Blaster was floating above him.

"I hurt you." He said softly. You weren't sure how to respond, your eyes fixed in fear at the large, deadly skull above him. After a moment of silence, another appeared.

"You didn't, I'm okay. Look." You said, slowly getting to your feet. All of your body felt weak after that much teleportation, but you knew you had to comfort Sans before something terrible happened.

"You're being sick. I made you sick!" He cried, his hands still pressed tightly over his face. A third blaster appeared, and all three were looking down at him.

"Sans, please. I'm okay. You're okay. Nothing bad has happened, and nothing bad needs to happen." You started walking towards him, your eyes still fixed on the blasters. You knew he wouldn't hurt you - it was more likely he'd end up hurting himself.

When you were close enough, you took a hold of one of his hands and slowly pulled it away from his face. He didn't react, didn't look at you, and you slowly pulled the other one away. Gently, you lifted his chin up so that he could look at you.

"I'm okay. I'm not hurt." He barely seemed to register your words, but he gently stroked one hand down your face as his tears ebbed away.

"You deserve the world. You deserve someone beautiful, strong, and perfect. Someone that can take care of you, and love you. Someone like Mettaton, I guess. Someone who's safe, who has all their shit together, who's not tearing up at the seams."

As soon as the words left his mouth, the jaws of the three Gaster Blasters above you unhinged, before pointing at the sky. Sans' eyes were pitch black as they fired brilliantly into the air.

"I  a m  d e s i g n e d  t o  b e  d e a d l y." As the hollow, grave words left his mouth, you saw Sans in all of his twisted glory. Illuminated by the brilliant white of the blasters, his skeleton lit up, every bone glowing with strong blue magic. In his ribcage, you could see what looked like a blue heart pulsing madly. His grin was different than any other, it was the grin of someone who had seen things you could never imagine.

You could feel it. All of his power, all the danger that emanated from him, all the magic he possessed.

Yet, none of you was afraid.

"You don't need to pretend around me, Sans." You said. The blasters above you disappeared as he regarded you, a confused expression crossing his empty eye sockets. "You don't need to try and scare me away. I'm not scared of you. I know you, you'd never hurt me."

There was a moment of silence, before Sans slowly pulled you into a tight embrace. It was different to the way he'd held you before - there was no desperation or fear in his grasp, only longing and need.

"There's so much..." He sniffed, inbetween small sobs. "There's just so much."

"I know, it's okay. Thank you for opening up like this." You comforted him, wrapping your arms firmly around his ribcage and nestling your face in the fur of his hood.

"Do you want to go inside?"

-

"Here." You said, as you handed Sans a mug of hot chocolate. He reached one bony arm out of the pile of blankets he was nestled in to grab it, before smiling at you gratefully. You looked around his room for somewhere to sit, but he patted the space beside him on his bed.

"Sit with me a while? I should probably explain what just happened." He said, weakly. You complied, sitting with him, before looking at him properly. The tears had dried whilst you were downstairs, and he'd undressed a little, leaving him in only a thin white t-shirt and his usual sweatpant shorts. It was at this point you realised you'd been in your date clothes this whole time, and you looked down at yourself, regarding the dress and high heels you were miraculously still wearing.

"Uh, actually, you do look a little uncomfortable." Sans said, noticing your line of sight. "Totally smoking, but not at all comfortable." He added. You nodded a little and started pulling your heels off.

"Yeah. Can't believe these damn things stayed on through all that teleporting." You replied, pulling them off and dropping them on the floor.

"You can just grab a t-shirt and shorts of mine, if you like." Sans offered, pulling his chest of drawers open, leaning far to his right so he wouldn't have to get out of bed.

You thanked him, before randomly pulling out some clothing, and changed into them just outside his closed door. You ended up in a pair of plain black shorts that reached your knees, and a red t-shirt that said _'wanna go to the bone zone?'_ on it.

As you got sat back next to Sans with your own hot chocolate and his smell drifting into your nose from his clothing, the skeleton began to talk.

"So, I don't know where to begin, but... I should tell you about Gaster, I guess. My father." He took a quick glance at you to make sure you'd settled in, before continuing. "Gaster, known to most as W. D. Gaster, was the royal scientist to Asgore in the underground for a long time. He created the Core, the huge facility that powered the underground through geothermal energy. Gaster was a man that was wholly dedicated to science. Everything he did, it was to further his knowledge of science and to push the boundaries of nature. That... is why my brother and I were created."

He stopped talking then, his face taking a pained expression, before he sniffed hard and looked up again. You didn't want to interrupt him.

"We were... experiments. He wanted to know if he could create... weapons, I guess. I don't know if you knew this, but Asgore was on the hunt for humans for most of our time underground. Monsters had a real problem with them and, uh, a lot of those who fell down there... didn't make it back up to the surface."

"Asgore... killed humans?" The words tumbled out of your mouth before you could stopped them. The only Asgore you knew was the fluffy, kind old chap that had only been pleasant to you. Next to you, Sans sighed.

"Yeah. He, uh, he killed a few kids, ____. But only because he had to - Monsters needed the power of the SOUL to get past the barrier, to free all monsters, and only a human SOUL could do that. He never wanted to do it."

You still struggled to absorbed this fact, but Sans pushed on through his story.

"So anyway, Gaster... he created Paps and I in order to try and create the ultimate human-killing weapons. I don't know what his main design was meant to be, but I'm sure this short stubby guy he ended up with wasn't what he wanted, so he then went on and created Paps, too. I mean, just look at my brother. He's much more tall and well-built than I am. Clearly, I was a failure from the start."

"You're not a failure." You reassured him, squeezing his free hand. He smiled at you gratefully but didn't stop talking.

"Clearly he was mad at himself for not getting what he wanted with me, so he started trying other things. He wanted Papyrus to be more powerful than he was, but didn't wanna fuck it up and have to create a third mouth to feed and take care of, so he started... experimenting."

Sans paused, his voice shaking on the final word, and you saw small tears form at the corners of his eye sockets.

"Hey, you don't have to tell me if you don't want." You said, worried. Sans shook his head.

"I want to tell you. This is important." He said, grasping your hand. You smiled and nodded, dreading the kinds of things he was about to tell you. You didn't want Sans to feel this pain.

"He started taking small pieces from the souls of fallen humans and... inserting them inside of me. I still remember being in his lab, being strapped to that table..." His voice cracked, but he regained his strength. "Over time, Gaster started seeing results from what he was doing to me. I gained abilities no monster had ever had before and he was determined to push me and push me, to do better, work harder, to be more powerful. After discovering my teleportation, he worked ruthlessly to make it faster, and to travel longer. He punished me brutally when I failed, and barely acknowledged my successes."

Sans was shaking hard, his bottom jaw trembling.

"He always thought the blasters were his greatest invention. The first time they happened, he'd just beaten me for not teleporting as fast as he'd like, and as he struck me this great big skull appeared above my head. I managed to get it to fire into the wall and not at him, but he wasn't even mad. He was overjoyed. He named them after himself, and trained me harder than ever before. I can make 'em appear whenever I like now, but it's still a knee-jerk reaction when I'm not feeling so great."

The image of him stood, yelling at the sky, with twenty blasters in the air above him filled your mind's eye.

"Anyway, one day he just vanished. Most people believe he just fell into the lava in the CORE, but I never did. My old man was a lotta things, but he wasn't clumsy. One day, whilst searching through his old stuff at his lab, I found this machine. I don't know what it does, and it was broken - with no way to fix it - but I'm sure that _that's_ what happened to him. I don't know where he is - the underground, in that machine, the void, an alternate universe - but I do know that wherever it is, he's too happy there to bother coming back. I never saw him since. The only nice part of my story is that ole' Paps never saw any of his abuse. He was too busy trying to perfect it on me."

A long pause occurred after he finished.

Gently, you shuffled closer to him and planted a kiss on his temple. He responded by putting an arm around your waist. After a few seconds, you rested your head on his shoulder and started speaking.

"You're here now, and you're safe. You've got all your friends, you still got Papyrus, and he's not here. He'll never hurt you here."

**Notes for the Chapter:**

> Thanks for reading babies!
> 
> I know it's all pretty angsty right now, but this is the last sad chapter before all the fun antics start again!
> 
> feel free to comment below, send me an ask on my tumblr at underblogger.tumblr.com , or tag a tumblr post with #UBTIAS
> 
> (If any of you end up drawing fan art of any part of the series - which I would die over - do tell me so I can link everyone else it!)


	19. Undyne Drops Papyrus Home From Their Sleepover

**Notes for the Chapter:**

> Hey y'all!!
> 
> Important info: I've updated the tags. This is because I didn't fully plan out the plot of the story before I wrote it. You may notice that mettaton/reader is now a tag - and it's not actually a spoiler, I just thought that since reader goes on a DATE with him it's probably something worth mentioning in the tags. If you think of any other updates I hsould add to the tags, tell me - because this story evolves beyond what I originally tagged and I'm not sure what is and isn't important enough to be tagged.
> 
> it's getting harder to update this as often as I used to because I'm revising for my summer exams now. I will still be updating this, but it's likely to be closer to 6 days than the usual 4! Sorry!
> 
> Also, a little Easter egg, if you look at the teleportation sequence from last chapter, you might see that Sans took reader to every important location for their relationship so far!

Silence fell after you spoke. It was a comfortable, rested silence of two people that finally understood each other. Heat seemed to emanate from every point of contact Sans' body had against yours. Even though he was just bone, he felt oddly soft and incredibly safe. The things you'd seen him do didn't make you even slightly afraid.

"So," Sans began, cutting through the quiet. "Is Mettaton a better kisser than I am?"

You gasped loudly in shock at this, before Sans started laughing loudly. Unable to keep the grin from spreading across your face, you smacked his shoulder lightly with the back of your hand. Feigning pain, Sans mockingly rubbed the spot you'd hit.

"Wouldn't you like to know, eh?" You smirked back at him flirtatiously.

"Ah, so you _did_ kiss him. Here's what I wanna know: does he have robot saliva, or is it all dry and rubbery?" He laughed back, raising a bony eyebrow at you. You snorted a little, before shaking your head.

"Unfortunately for you, Sans, I don't kiss and tell." You replied, crossing your arms and sticking your nose in the air.

"Aw, come on babe. Just give me one tiny hint? One little detail?" He bargained, shuffling closer to you. Part of you wanted to give in to him, feeling weak from this close physical contact, but you tried to stay strong. You didn't even dispute the pet name, it just sounded _right_ coming out of his mouth.

"Can you imagine if I told Mettaton what kind of kisser _you_ are?" You retorted. Sans shrugged.

"I wouldn't mind, 'cause you'd only tell him how great I am." He finished his confidence drawl with a wink that drew back every memory you'd almost forgotten of how goddamn sexy Sans could be.

"Well jeez..." You said, faking innocence, "It's just been so _long_ since we've kissed properly that I might've just _forgotten_ how - "

Sans cut you off by pressing his lips to yours. Unlike earlier, this was far more controlled and slow. Gently, his magic tongue probed gently at your lips. It didn't take long for you to give in and let him in, his slow kiss lulling you into a smooth, pleasant rhythm. His mouth was just the right amount of wet, his speed was just right, and his gentle hold of your sides was just enough pressure to make you want more. Unable to help yourself, you moaned softly against his mouth. Upon hearing this, he gripped you tighter and kissed you harder. It was enough to drive you crazy.

"I'll never let you forget again." Sans growled softly as he pulled away. Every smart comment that you'd thought of saying was whisked immediately out of your mind. Your world was Sans, and he was finally right here in front of you.

"I... uh... wow." You stuttered weakly. It seemed impossible, but it felt like he had _improved_ since last time.

"I don't want to push you. You've just gone on a date with another man, and we've just had a dramatic moment - your emotions are bound to be running wild right now." Sans said, gently. "I want you. I want you so, _so_ badly. But, I know that it would be unfair to do anything right now, considering everything that's just gone on."

This wave of practicality brought you back to reality. You had _just_ been on a date with Mettaton - on which he'd paid for the _whole meal_ \- and Sans _had_ still hurt your feelings. The feeling of his kiss still ran amok through your mind in a tornado of lust, but the concealed look of hurt on Mettaton's face as you'd suddenly pulled away lingered in your mind longer.

"Yeah." You said dumbly, the cogs still turning in your mind. "Yeah, you should probably get some sleep anyway."

"I should." Sans nodded. There was a brief pause, in which you knew that he wanted you to stay with him as much as you wanted to stay, but you shifted away and got off his bed. You glanced at him one last time as you left his room, before you walked slowly into your own.

As soon as you were alone, tiredness hit you like a brick wall. You hadn't thought it was possible for someone to feel so much in one evening. Exhaustion drained you of every emotion. Tomorrow, you were just going to watch crappy TV shows al day.

As you got into bed, it briefly passed your mind that you should change out of Sans' clothes and into your pyjamas, but his smell coming from them and the knowledge that they were his was too powerful for you to do anything about it.

-

"And then you just _broke it off_?! _How_?!" Undyne cried, waving her arms wildly in the air. You laughed.

"I just stopped kissing him! It wasn't that hard!" You laughed. Telling Undyne all the events of the night before was hilarious, as she'd over-reacted to every little detail. Her coffee and breakfast croissant were in great danger of being flung across the room.

"But then what?" Undyne probed eagerly. It was impossible not to laugh at how enthusiastic she was.

"Well, I went home, saw Sans, and went to bed - "

"No, you can't skip over that! You argued like that and then what, you just 'saw Sans'?! No way. I want all the details."

"Undyne, I honestly didn't really - "

"I don't buy any of it! You _must've_ at least spoken to him."

"Well..."

" _Yes_?!"

"He told me he liked me."

Upon hearing this, Undyne punched her fist into the air in victory. You wanted to carefully avoid the more sensitive events, as even though Sans hadn't  _told_ you what he'd said was a secret - it clearly was.

"I _knew_ it!" She cried loudly. It was hard not to laugh again. She was so loud, you were thankful Papyrus and Sans had gone on a walk as soon as Undyne had arrived to drop him off from their sleepover the night before.

"Yeah. Then we kissed, it was great, but then he got serious. He said he was trying not to push me or anything, since I'd just gone on a date with Mettaton - which makes sense. I don't want to hurt Mettaton at all, he's a really great guy and it was actually a great date up until Sans interrupted it. It _was_ a good kiss though." You rambled slightly as you spoke quickly in order to get all the words out before Undyne could interrupt you. Surprisingly, she was more thoughtful than excited.

"Yeah, Mett... I'm glad you're thinking about him amongst all this. Behind all the ridiculousness, he's a sensitive soul." It was odd to hear Undyne speaking so quietly.

"Yeah... I'm a little stuck now." You said, thinking about the two monsters you'd managed to attract.

"What do you mean?" Undyne asked, cocking her head to one side. The end of her ponytail was dangerously close to dipping in her coffee.

"Well, Sans is really sexy and drives me wild, but he can be a little unpredictable and he's hurt me before. On the other hand, Mettaton is a gentleman, he would never hurt me, and he's got great financial prospects." You explained, thinking about the two of them. Even though it seemed clear Mettaton was the logically better choice, a part of your brain refused to admit it. It was like Sans had hooked your brain in, like a fishing rod to a fish.

"I see your problem. Let's make a battle plan -  go on a date with both of them, separately, and see which you enjoy most." She offered. You considered it. It felt like a good way to really see which you preferred - even if you kind of knew which one you wanted any way.

"That actually sounds like a good idea." You said thoughtfully, before laughing. "I can't imagine Sans being very romantic on a date, though." Next to you, Undyne chuckled.

"Maybe he'll surprise you. I hear the spilled drinks and stained seats of Grillby's make for the perfect romantic setting." She retorted. You snorted with laughter.

"Between Sans and Grillby himself, perhaps."

At this, Undyne threw her head back and laughed wildly. It took a few minute to wipe the tears out of your eyes.

You felt a buzz in your pocket and gently fished out your mobile phone. It took a few seconds to pull it out of your pocket.

Mettaton was calling you.

**Notes for the Chapter:**

> Thanks for reading! As always, feel free to leave a comment below, send me an ask on my tumblr at underblogger.tumblr.com , or tag a tumblr post with #UBTIAS !
> 
> I love reading everything you guys tell me about this - I'm having so much fun.
> 
> For those wanting smut - just hold on. We're getting closer now...


	20. You Finally Choose One

**Notes for the Chapter:**

> This is late! Sorry! I planned to upload days ago, but I ended up getting really sick with a migraine and going anywhere near a computer killed my brain.

There was silence on the phone line for a few seconds. In the moment of quiet, all the moments from your date with him ran through your head. How much you'd enjoyed yourself, Sans showing up, going back to Mettaton's place, making out...

"Hey, Mett." You said gently. On the other end of the line, you could hear his metallic body humming gently.

"Hello, darling. Are you alright after last night?" His voice was full of concern, and it pained your heart. Guilt over how you'd left things could've swallowed you whole.

"Yeah, I'm much better, thanks. I'm sorry about - "

"It's okay, you don't need to worry about it!" He hurriedly cut over you. "It's perfectly alright. I can imagine how shaken you must've been after we were interrupted."

"Well, thank you, but it's no excuse. I shouldn't have just abruptly left like that." You said, fiddling with your hair absent-mindedly. "Look, do you want to go on another date?" There was a brief pause where the robot didn't reply, causing you to nervously glance at Undyne, who was eagerly listening in from the other side of your kitchen table. She grinned at you and held her two thumbs up.

"That would be lovely." He warmly replied, causing you to let out a long breath that you didn't realise you'd been holding in. "I know it's short notice, but I can pick you up after work tomorrow?"

"Sounds great!" You replied, a little eagerly. The sooner you could sort out this lusty mess, the better. Mettaton hummed a happy tune to himself as Undyne clapped her hands excitedly.

"I'll see you then, darling." The TV star smoothly replied, before hanging up. As you put down the phone, Undyne squealed out loud.

"I can't wait to tell Alphys!" She cried, laughing slightly. A blush filled your cheeks.

"You're so childish! It's very hard to concentrate on talking to him when you're right there." You scolded her, but failed to sound stern. A small grin tugged at the corners of your mouth.

"So." She began, rubbing her hands together.

"So." You repeated, taking in a deep breath. "Time to date a robot, and then a skeleton."

-

You spent most of Sunday and all of Monday thinking about the date. The fact that you didn't know where you were going to be having the date scared you a little, as it meant you didn't really know what to wear. After work at 9:30, you changed in the bathroom into a nice black skirt and a cute strappy top, along with a black clutch bag that had your essentials inside. When you reached the door, Mettaton was stood outside waiting for you.

"Darling! You look absolutely ravishing." He gushed, offering you his arm and gesturing towards the limo behind him. All around you, your co-workers gasped and giggled in his presence. Your cheeks burned and you ducked into his shoulder to try and hide it - it would take you weeks for them to stop talking about this. As you got to his car, he stepped ahead of you to open your door. You graciously stepped inside, thanking him, and he walked around the other side to get in. He didn't need to say anything to the driver - clearly he already knew where Mettaton was taking you.

"How has your day been?" He asked you as he opened a compartment in the centre console of the car. From it, he took a bottle of champagne and a single glass.

"Okay! A little tiring, but that's work I guess. What about you?" You questioned, accepting the glass of champagne he gave you. It felt nervous to hold it - you really didn't want to spill any in his wonderful (and clearly expensive) car.

"Oh, the usual! Interviews, press announcements, photo shoots..." He waved a hand uncaringly. It was kind of shocking to see him be so nonchalant about his job, when it was so interesting to you.

"But that's exciting!" You protested, looking over at him. He smiled lazily, and it sort of reminded you of Sans.

"Not as exciting as you." He smoothly replied, leaning further towards you. His eyes briefly flicked towards the window and he gasped. "We're here!"

You turned around to see that you'd arrived at a large building, with a huge plaque above its large wooden doors. It read, _'Midnight',_ and from inside you could hear loud, thumping music. By the time you'd processed that Mettaton had taken you to a nightclub, he'd already walked around and opened your door for you. As you stepped outside, he took you by the arm and led you confidently inside.

The air inside was stifling, noisy, and humid. The doors opened to a balcony that overlooked a large dance-floor, already full of people moving in fluid, drunken motions. The room itself was massive, with black bricked walls and a colourful bar near to the DJ's booth. A man was stood on the corner, checking the IDs of a cat-girl monster and crocodile-girl monster, who looked a little like they were trying to sell him something in the process. Upon seeing Mettaton, the doorman straightened up, smiled, and adjusted his tie.

"Your booth is prepared as always, sir." He gulped, a trace of nervousness seeping into his voice. Your robotic date simply smiled gently and nodded as he led you down a set of stairs to your right.

"Your... booth?" You questioned, calling loudly above the music. Mettaton laughed.

"I come here often, so they keep the same place free for me whenever I'm here." He explained, his face close to yours as he spoke directly into your ear. It was odd, knowing that he was right next to you but not feeling the usual biological tells of this, like body heat or breath.

As you reached the dance floor at the bottom of the stairs, a few girls nearby recognised your date and started pointed behind gasps and giggles. As you walked past them, one of them squealed loudly, hiding an embarrassed blush behind her hands. Mettaton stopped suddenly, and turned to look at their group.

"Sorry, did I hear one of you say my name?" He gently inquired, wrapping a hand around your waist as he walked over to them. The girl who had caught his attention shook her heard rapidly, her blonde hair swaying around her shoulders. One of her friends laughed and pushed her forwards.

"Beth! Don't be an idiot!" The other girl said as 'Beth' ended square in front of Mettaton. "Sorry, my friend's just shy, she's a big fan of yours." The other girl said. Upon hearing this, Mettaton swept forwards, away from you, to gently take her hand.

"Is this true?" He gently asked. Beth bit her lip and nodded, the furious red blush not leaving her pretty face. Mettaton chuckled gently, and steeped closer.

"Then I am very glad you like my work." He smoothly said, before kissing the hand he held. As soon as he'd done it, he immediately let go of her hand and walked back to you, leading you away into the crowd. It didn't take you long to get to the other side of the dance floor, as many other people had started to recognise who Mettaton was and step out of his way. Your mind was still reeling from what had just happened, the image of Mettaton kissing another girl - albeit on the hand - was not something you'd expected him to do on your date with him. You reached a door to the left of the vibrant bar, with led to a back room that looks more like a vast hallway than part of a club. It had the same black walls as the dance-floor, but this time instead of a crowd of people, there was a row of black windows.

"Here, darling. Sit down and I'll go get you a drink." Mettaton said gracefully as he opened a door in the blacked-out window in the centre of the hallway. Inside was a circular room that had a plush, rounded red sofa with a black table in the centre. You could only nod as you sat down, trying to take in your surroundings. Once you were alone, you adjusted the kitten heels you were wearing, and opened your bag. You had a text from Sans. It was probably wrong to text another guy you were interested in on a date with somebody else, but you couldn't resist opening it - since you were alone.

21:35 sans: **how was your day? got a skele-tonne of work done? ;)**

You rolled your eyes, and laughed under your breath. You knew you had to try and one-up him.

21:51 ____: **It was alright. Why, were you bone-ly without me? ;)**

As soon as it sent, the door of the booth opened and you shoved your phone back into your bag, feeling slightly guilty.

"Here! I just know you'll love this." Mettaton smiled as he cosied up next to you on the sofa. Handing you a tall glass with vibrant yellow liquid inside it, the robot wrapped an arm around you and bit his lip gently.

"Thanks!" You warmly replied. There was a second of silence, as Mettaton continued to gaze at you, his eyes scouring every inch of your face. He held an expression of adoration that you hadn't expected to earn from him. You felt kind of awkward.

You slowly took a sip of the drink he had handed you, and gasped instantly. It tasted exquisite. There was a tangy, citrus undertone that was gently mixed with a creamy texture that combined to make one of the nicest drinks you'd ever had in a club. If you didn't know better, you wouldn't have even known that alcohol was in it.

The conversation passed easily and flowed smoothly - Mettaton was an excellent conversationalist, and even though it was just the two of you, there didn't seem to be a moment of silence. Your TV star date was great at sticking to safe, yet interesting subjects, whilst carefully avoiding anything that might upset either of you. It was nice to be able to just talk about whatever was on your mind - instead of your love life, which was what everyone else had wanted to talk about recently.

However, whilst you were having a nice time, there was one thing that kept creeping back into your mind: Sans. Every time one of you left to go to the bar, it crossed your mind that whilst you were alone, you could check to see if Sans had replied to you. Every time Mettaton made a joke, you would wonder if Sans could've made a funnier one.

It was frustrating, because you knew Mettaton should be the right one for you. As a boyfriend, Mettaton was a true gentleman - kind, caring, funny, and willing to always listen to what you wanted and had to say. As well as that, you couldn't ignore how Mettaton was secure financially, and had an excellent, thriving career. He was perfect. Although, that was sort of the problem. Mettaton was _too_ perfect.

"I've had an excellent night." You smiled, as Mettaton walked you to your door later that evening.

"I'm glad, so have I." He warmly smiled. As you stood outside your door, he looked deeply into your eyes for a second, before taking your hand and kissing it, the same way he had to one of his fan. Confusion flicked over you - you'd been expecting him to want a real kiss.

"It's been fun dating." He simply said, before walking back to his car. You stood still for a second, puzzled, before your door opened behind you.

"Hey. All dolled up for another man again?" A gruff voice asked. You spun round quickly to see Sans leaning against the door frame, dressed in his usual attire of sweatpants, a white tee, his big blue hoodie, and a pair of pink slippers.

"I... well... yes?" You nervously replied. However, instead of the anger you'd seen before, Sans simply laughed and stepped aside, letting you in.

"It's ok. You look a little scared, which I guess is my fault. I'm not gonna freak out again." He assured you, watching wistfully as you pulled off your heels.

"Well, I think I just got broken up with." You slowly said as you straightened up, thinking about what had just happened. There had been some sort of understanding between the two of you, and sympathy in Mettaton's eyes.

"What? Really?" Sans questioned, sounding a little eager. You chuckled at his inability to keep control of himself.

"I see you're very sympathetic." You said, as if scolding him. He suddenly looked guilty, and stepped hurriedly towards you. "It's ok. There was no spark, no chemistry. I'm not upset."

"That's good then, I guess." He said, not moving away. His skeletal hands gently traced lines down your arms, before fiddling with your fingers. You looked down at them slowly, before gazing up into his eyes.

"Oh it's good, is it?" You grinned, torturing him. The one thing on his mind was clear in his eyes; _victory_.

"It's, well... stop twisting my words!" He grinding his teeth together frustratedly.

"Sorry, I'll stop." You laughed.

"I'll forgive you if you let me do one thing." He said, tilting his head inquisitively as his fingers continued to fiddle with your own, inter-twining and un-hooking over and over. You wished he would just take your hands properly.

"Sure." You said, a little quickly, as you firmly took his hands in yours. Sans looked briefly down at them , before smirking smugly and looking back into your eyes.

"Let _me_ take you on a date instead, baby."

**Notes for the Chapter:**

> Thanks for reading! As always, feel free to comment below, send me an ask at my tumblr at underblogger.tumblr.com , or tag a tumblr post with #UBTIAS !


	21. You Suck At Shooting And Driving Games

**Notes for the Chapter:**

> Yo! I hope you like this, I had fun writing it!
> 
> I have fun writing this whole story. It's great.

It was Friday, and you were nervously stood in the hallway of your house. Upstairs, you could hear thudding as Sans was hurrying around his room. Butterflies fluttered around your stomach as you checked your makeup in the mirror for the millionth time. Sans had told you to just wear casual clothes, so you were in your favourite jeans and a simple, yet pretty top. It felt ridiculous to be so tense, when you'd already touched your date's glowing blue dick.

"I'm ready, I'm not late, I'm ready!" Sans called as he ran down the stairs. You turned to see him in a pair of black jeans, with a shirt and blazer that looked unusually smart - considering it was _Sans._

"You look nice." You noted, watching him check he'd buttoned his shirt up correctly and pulling some high tops on. He looked up at you as he bent over and flashed you a cheeky grin.

"I could say the same for you, sweet cheeks." He drawled. As he straightened up and pulled his blazer into place, you saw something flash over his eyes - a nervousness that matched yours.

"You still haven't told me where we're going." You complained. The skeleton in front of you only grinned and swung open your front door, chuckling slightly.

"It's not a surprise if I tell you. And, y'know," He paused, turning to look at you as he absentmindedly held the door open behind him, "you should probably prepare for a few surprises tonight."

-

"An arcade." You muttered as Sans swung his arms out in front of him dramatically.

"Ta-da!" He exclaimed proudly. "Bam, surprise! Location!" His enthusiasm made you laugh - it was very refreshing to be around him when he was this happy.

"It's awesome!" You eagerly replied, clapping your hands together. In front of you was the arcade in your local shopping centre, it's bright lights and loud chiptune songs spilling out into the rest of the large hall you stood inside. Sans took your hand wordlessly and led you inside, stopping in front of two dance mats.

"Dare to challenge me in the _ultimate dance battle?!_ " He cried, jumping onto one of the metal mats.

"Oh it's _on_ , bone boy. You can't beat _me_ \- I'm the dance _master!_ " You laughed back, before jumping onto the other mat. Sans chose a very fast paced song, and you giggled out of excitement as it began. At first it was hard to keep up with the quickly falling arrows, but soon enough you were switching and swapping your feet enough to call yourself a pro. Clearly, you were naturally good at this, and it made it even more satisfying that Sans was failing miserably next to you.

"Hah! You see?! I'm the _best_ at this!" You gloated, after winning the third song in a row. Next to you, Sans was audibly growling from frustration.

"Fine, you win dance mats. Let's play a different game." He grunted, hopping off the mat ungraciously.

"Hey hey, don't be a sore loser!" You whined as you followed him. It would be no fun to be here if Sans was going to be a little kid about losing.

"Let's make this interesting." Sans suddenly said, turning around to face you.

"Okay, sure." You said slowly, not knowing what he was going to propose.

"Tell you what - I've already got plans for dinner, but the first to win 5 arcade games decides what happens at the end of the night." His voice grew less angry the more he talked - clearly he thought he would be better at different games.

"Sounds good!" You grinned. His idea was a good one, but it made you a little apprehensive. You weren't sure what Sans would ask for if he won.

You moved on to a shooting game, where bugs flew at you whilst you drove inside a safari car. Needless to say, Sans wiped the floor with you as he scored nearly 4 times what you could achieve. The smug grin he gave you each time he won was maddening enough, never mind how he would laugh heartily whenever your character died. Determined not to lose hope, you chose a racing game to play next - but quickly realised your mistake as Sans immediately hopped onto one of the two motorbikes and stuck his tongue out at you. _Of course_ , you thought. _Sans has a motorbike of his own, why on Earth did I pick this?!_

"Two out of five!" Sans whooped as he crossed the line a full lap before you did. "Ready to lose, sucker?"

"Not over my dead body, _bone head_." You angrily grumbled. You _had_ to win the next game.

"Woah woah, just a game." Sans winked. "Tell you what, I'm feeling nice, you wanna pick the next game?"

"Sure." You said, calming down as you looked around the arcade. "Uh, you wanna try those basketball machines?"

-

The atmosphere was tense as you looked over at Sans. It rode on this last throw - if he got it in, the you both were tied and you'd have to have another round to decide who won. However, if he lost, you would be the winner and you'd be drawing with him overall with 2 games each.

"Come on." You urged, after a solid minute of no action. Clearly, he was trying to take his time to aim the shot.

"Shush. Gimme a minute." He said under his breath, still staring intensely at the hoop in front of him. After a second, he threw the ball. It flew through the air, heading straight towards the hoop. You could almost taste his smugness. Suddenly, it bounced off the side of the hoop, and rattled down the cage below. He'd lost.

"Take _THAT_!" You cried triumphantly. Next to you, your date ground his teeth together and frowned.

"Alright, alright, you won. I wanna choose the next game."

-

Sans had won at Tetris, but you beat him at the horse racing and whack-a-mole , which had brought you to this. At the other end of the air hockey table, Sans was grinning madly.

"Confident?" You asked, as he chuckled.

"Very. With this game, I have an ace up my sleeve." His grin was so smug, it could kill you if you looked at it too much.

"We'll see about that." You replied. "Wanna take the first hit?"

You'd agreed that the first to ten would be the winner and it felt like Sans got to 7-0 it two seconds. It was inexplicable - every single match, he would get the annoying blue puck into your goal almost immediately, even though it barely seemed like he was hitting it.

"You're getting your ass whooped." Sans pointed out as he lined up the puck for round 8.

"I just don't understand how you're doing this!" You cried, running a hand through your hair. "You're so good, but I don't get how! It doesn't seem humanly possible!"

"Well baby, I'm not human." He winked, setting up the puck. As he hit it quickly towards you, his words echoed in your mind.

_I'm not human._

Realisation flew through you as you whacked the puck back to him. _Sans wasn't human._

"Hah!" You yelled as you suddenly grabbed the puck. Slight resistance kept it on the table, but as soon as you held it in the air it became obvious what had happened. In your hand, the bright blue puck suddenly fizzled slightly, and became grey before your very eyes. Sans had been using his magic to cheat.

"You are a filthy liar!" You exclaimed, using your free hand to point accusingly at him. "You've been using your magic to push it into my goal this whole time!" Across the table, Sans looked shocked, then annoyed, and then guilty.

"I didn't think you'd work that out." He said dumbly, staring at the puck in your hand. Slowly, anger crossed his features again. "I was so close to winning, too!"

"Yes, well, you _cheat_ ," You continued to scold him, thoroughly enjoying yourself. "Since you didn't play fair, that means I get the point."

"Fine." Sans growled in response, dropping his paddle harshly onto the table.

"That means... I'm on five points!" You suddenly realised. "I win!"

" _Fuck!_ " Sans shouted, before clapping a hand over his mouth as a child walked by with their very disapproving mother.

"I won! I'm officially the best!" You continued to celebrate as you danced around the table. Sans caught you once you got to him, his bony hands wrapping around your waist.

"Yeah, you win this time. Wanna go get some dinner now? I'm gonna take you to my favourite place to eat."

-

"This is... not what I was expecting." You thought out loud, your stomach settling from the teleportation as Sans set up his hot dog stand.

"You don't like it?" Sans suddenly asked, his face full worry. "I should've thought this through better I guess, I didn't know if you wanted a fancy meal, I know the robot would've taken you somewhere posh - "

"I do like it!" You assured him quickly, cutting his rant off. "It's great, and very personal! I just wasn't expecting it." He looked comforted as he handed you the stool. You sat on it thankfully, as Sans opened up the inside of his stand. Very quickly, he made two hot dogs, slathered his in way too much ketchup, before sitting on the counter.

"Thank you!" You smiled as you took a hotdog from him. You had to admit, he was very good at making them. It was silent for a few minutes as you both simply ate, enjoying the taste of the food and the view of the bright city lights all around you. It was wonderful to take a minute to enjoy your surroundings and watch other people rushing past whilst you were still, peaceful, in your own little world.

"So." Sans began as he finished his hot dog. "Do you know what you wanna do? Since you won our bet, and all." You began to think seriously as you finished your last mouthful of the hot dog.

"Not too sure yet." You mumbled as you swallowed your food. In front of you, Sans chuckled as he jumped from the counter and slowly walked over to you.

"You've got a little spot of ketchup on your face." He said, before he stroked a finger over the side of your mouth. You could only watch in relative shock as he slowly put his finger into his mouth. You caught a glimpse of his bright blue tongue licking the red sauce off his finger.

There was a pause as you watched that bright blue tongue, and Sans looked intently at your lips. Neither of you spoke, before you both suddenly crashed together. It was so fast that when you kissed Sans, he hadn't been quite ready and your lips crashed into bone. However, it didn't take long for his magic to start working and soon you were both kissing passionately, his hands on your waist as you wrapped your arms around his neck. It was exquisite. Sans could expertly take control of the kiss with ease, his lips guiding yours open as his magic tongue slipped delicately in your mouth. In one lusty second, you imagine the various other places that you'd like his tongue to be. As you pulled deeper into the kiss, you briefly felt like your legs had turned to jelly, before solid ground flew under your feet again. You slipped one eye open to find that Sans had teleported the two of you to his room.

"I know what I want." You suddenly said, breaking the kiss.

"What?" Sans questioned breathily, confusion passing over his skeletal face.

"I know where I want the evening to go." You panted, glancing around the room. He'd made his bed.

"Where?" He asked, his eyes desperately searching yours. A wave of passion flew through you as you pulled him closer to you.

"Fuck me."

**Notes for the Chapter:**

> I'm sorry for leaving it there! But I'm also not sorry because I'm evil and I enjoy it. Seriously though, the chapter was getting super long, so you'll just have to wait until next time!
> 
> As always, feel free to leave a comment below, send me an ask on my tumblr at underblogger.tumblr.com , or tag a tumblr post with #UBTIAS !


	22. Satisfaction

**Notes for the Chapter:**

> Warning: Smut!

Sans moaned loudly as he hurriedly ripped open his shirt, sending buttons popping across his room. You would've thought about how that was a waste of a perfectly good shirt, but the sight it revealed washed away any other thoughts from your mind.

Sans' chest was lit up brightly, causing a strange blue glow to fill the dark room. In the centre of his rib cage was a deep blue heart that pulsed wildly as it constantly expulsed blue smoke. This light blue smoke curled delicately around the rest of his rib cage, weaving in and out of his ribs, but never straying away from his main body. You could barely tear your eyes away to look back up at his face.

"It's rude to stare." Sans chuckled, as he tilted your face up gently with your palm. Your eyes met his, and you saw that his left eye was already glowing brightly.

"It's... beautiful." You managed, sneaking a peek back down at his ribcage.

"So are you, baby." He gently replied, as he pulled your top over your head. You helped him by lifting your arms and unhooking your bra, and as soon as it was off the same look you'd seen on his face before crossed his skeletal features. Hungry glee and desperate adoration dominated his eyes as he gently started to tweak your nipples with his soft bony fingers. Every time you gasped, his delighted grin grew wider.

After your nipples were thoroughly hardened, he leant down and pinched your left nipple in his teeth, the pressure causing arousal to burn in your stomach. As you threw your head backwards, your hand rested on the back of his skull, he took it into his mouth properly and that devilish tongue of his started working it's magic. As he licked and sucked, he gently groped and squeezed your other breath with his free hand. When he'd finished playing with your tits, Sans started gently kissing down your stomach, his teeth nipping your skin every so often, before he reached the waistband of your jeans.

"Take them off." You begged as he looked up at your for permission. Complying immediately, the monster at your feet roughly tugged them open and pulled the denim down to your ankles. He took a second as you stepped out of your jeans, and he chuckled gently as he ran a finger along the hemline of your panties.

"Nice." He grinned, looking at them appreciatively.

"Well, they could be nicer, but _someone_ still has my nicest underwear hidden." You retorted, wishing that you could've been wearing your nice lacy panties for this - especially as you had a bra that matched.

"Mmm, I know. Those are really nice ones, too." Sans groaned gently, glancing up at you. "However, making you find them is just as fun as seeing you in them."

You opened your mouth to try and convince him to just tell you where your panties were but you fell silent as he suddenly tugged yours down. You heard him sharply intake a breath as he faced your womanhood. You could feel his warm breath brushing against your labia as a slow, smug grin tugged at the corners of his mouth. Slowly, you felt him insert one finger inside you, and then two. You couldn't help but whimper gently as he pumped them in and out, keeping intense eye contact with you, before he stood up again.

"Take off my trousers." He growled, as he put his fingers into his mouth. He hummed appreciatively, the sound interspersed with sloppy sucking noises. The fact that he was tasting you set your arousal ablaze. You wanted him. You needed him. A sense of awe filled your mind again as you roughly tugged Sans' briefs down with his boxers. The same blue smoke that filled his ribcage curled down to fill his pelvis. As you watched, some of it curled together to form a glowing blue phallic shape you'd already seen before.

"God, that's incredible." You breathed as you reached down to stroke it. At your touch, Sans tensed up slightly and a long, loud groan escaped him

"Fuck, I forgot how good that feels." He moaned as he tipped his head back. His tongue lolled slightly in his open jaw, and a look of ecstasy captivated his features whilst you started to pump your hand back and forth.

"Okay." Sans said after a few seconds. "We should take this to the bed." He explained as he gently pushed you backwards. When you felt the edge of his mattress press into the backs of your thighs, you turned to swiftly climb onto it - but not before you felt a bony hand graze over your exposed ass.

"Hey!" You exclaimed, surprised, but Sans only shrugged cheekily when you turned to look at him. You giggled slightly, but any urge to laugh was suppressed when he got on the bed and positioned himself above you. In this position, you couldn't help but marvel at his magical and incredible body - as well as the smoke that unfurled around his chest and crotch and the impressive size of his dick.

"You still okay with this?" He gently checked as his eyes followed where yours were looking.

"Totally. God, I want you so bad." You replied. The second you confirmed, Sans shifted into place slightly before thrusting forward and entering you. The feeling of being filled was exquisite, as well as the satisfaction of finally doing this.

"Fuck!" He exclaimed loudly. His breath grew haggard as he slowly drew himself out of you and then thrust back in again. After a few slow pumps in and out, he started to pick up a faster rhythm as his hard cock entered you over and over again. He was supporting himself with one hand, but the other roamed freely over your chest as he fucked you.

"This feels so fucking good, baby." He moaned as he picked up the pace slightly. His words ignited your arousal further, and you couldn't help but moan. You gently placed one of your hands on his shoulder as he continued to fuck you, whilst the other roamed down the side of his ribcage. It was hard not to be fascinated with the way that the smoke curled around your fingers and covered your hand slightly. When you ran your finger on the inside of one of Sans' wrists, he groaned loudly.

"Oh, you like that?" You asked, a small smile forming on your lips. Your voice has husky and heavy with lust, the pants heaving out of your chest matching the ones that Sans was making.

"Fuck yes. Do that again for me." His words were full of pleasure, but there was no pleading - Sans was thoroughly in control. The very thought caused hot lust to wash over you and you roughly wrapped your fingers all the way around a rib close to the blue heart in his chest, gripping it tightly in your hand. As soon as you did it, Sans let out a wild, animalistic groan.

"Fuck, you're putty in my hands." You smirked up at him. As you spoke, he suddenly stopped thrusting, still inside you, and leaned closer to you.

"I don't think you realise who is in control here." Sans slowly said, his deep voice growing darker and darker. "You. Are. Mine." He punctuated each word with a hard thrust - causing you to cry out each time - and as he did it, something was changing. It became more and more evident as he slowly entered you again that his cock was growing larger by the second, filling you to an extent you'd not thought possible.

"Fuck - please - " You incoherently moaned, unsure of what you were really asking but thoroughly enjoying yourself.

"Does it hurt?" Sans asked as he continued to penetrate you. You could only shake your head meekly. At this, he nodded and sped up again - but this time he reached his free hand down between your legs and started rubbing your clit in circles. It was too much to take. The combined bliss of his huge cock stuffing you and the coiling bliss of the attention of your clit was driving you closer and closer to orgasm - and you weren't sure if you could hold on much longer.

"Fuck, Sans, I'm gonna - " You cried, feeling your orgasm building quickly.

"Don't cum until I say." Sans breathily replied, the pace of his rubbing finger decreasing. After a few seconds of torture, where all you wanted to do was cum, he let out a held breath and looked back down at you.

"Okay." He said, his voice rasping. "Cum." You cried out immediately as he sped up his pace again, and your orgasm washed over you. As pleasure crashed through you heard his moans grow louder and more wanton whilst his thrusts grew slower, signalling his climax. You could feel his hot seed fill you up as he groaned one last time and practically collapsed on top of you. It took a few seconds before either of you had enough breath to speak.

"That was... incredible." You said, your voice cutting through the heavy pants that filled the air.

"Yes it was." Sans agreed, rolling off of you. After a few seconds, the glow next to you started to subside, and you tilted your head to look at your skeletal lover.

"You came inside me." You suddenly said, thinking about what had just happened. Nervousness immediately took hold of you - you weren't on any birth medication at the moment.

"Don't worry." Sans smiled, brushing a hand against your cheek. "It'll just fade away as my magic does. Monsters work differently to humans - especially monsters like me." His words comforted you, and the anxiety and fears of having to go get a morning after pill were extinguished.

"Great. I was a little worried for a second." You admitted.

"You shouldn't be. I wouldn't do something like that to you. Steal your panties, sure, but actually put you in danger or harm? Never. You're safe with me." He assured you, one of his hands twiddling your hair.

"Thank you. I know." You smiled at him sleepily.

"Come on, time for bed." Sans said as he held his hand in the air. After a flash of blue, an oversized tee gently tugged itself over your head, and you looked over to see that Sans was tugged on a pair of baggy boxers, a black tee already on his body. You tugged on a spare pair of his underwear that were hanging in the air in front of you, before Sans pulled you over to him and wrapped the sheets around you both.

Sans' cuddles were the last thing you felt before you drifted off to sleep. Finally, everything was peaceful between you.

**Notes for the Chapter:**

> Wow, did I just write... fluff? that would mean that I've written two firsts in this fic, smut and fluff, all in one chapter XD
> 
> Thanks for reading! As always, feel free to leave a comment below, send me an ask on my tumblr at underblogger.tumblr.com , or tag a tumblr post with #UBTIAS !


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